ORCID Profile
0000-0003-0882-4728
Current Organisation
University of New South Wales
Does something not look right? The information on this page has been harvested from data sources that may not be up to date. We continue to work with information providers to improve coverage and quality. To report an issue, use the Feedback Form.
In Research Link Australia (RLA), "Research Topics" refer to ANZSRC FOR and SEO codes. These topics are either sourced from ANZSRC FOR and SEO codes listed in researchers' related grants or generated by a large language model (LLM) based on their publications.
Materials engineering | Functional materials | Composite and hybrid materials
Publisher: Wiley
Date: 27-11-2021
Abstract: The surface chemistry of colloidal quantum dots (CQD) play a crucial role in fabricating highly efficient and stable solar cells. However, as‐synthesized PbS CQDs are significantly off‐stoichiometric and contain inhomogeneously distributed S and Pb atoms at the surface, which results in undercharged Pb atoms, dangling bonds of S atoms and uncapped sites, thus causing surface trap states. Moreover, conventional ligand exchange processes cannot efficiently eliminate these undesired atom configurations and defect sites. Here, potassium triiodide (KI 3 ) additives are combined with conventional PbX 2 matrix ligands to simultaneously eliminate the undercharged Pb species and dangling S sites via reacting with molecular I 2 generated from the reversible reaction KI 3 ⇌ I 2 + KI. Meanwhile, high surface coverage shells on PbS CQDs are built via PbX 2 and KI ligands. The implementation of KI 3 additives remarkably suppresses the surface trap states and enhances the device stability due to the surface chemistry optimization. The resultant solar cells achieve the best power convention efficiency of 12.1% and retain 94% of its initial efficiency under 20 h continuous operation in air, while the control devices with KI additive deliver an efficiency of 11.0% and retains 87% of their initial efficiency under the same conditions.
Publisher: Wiley
Date: 31-01-2018
Publisher: American Chemical Society (ACS)
Date: 20-05-2020
Publisher: Wiley
Date: 03-05-2021
Abstract: Organic–inorganic mixed halide perovskites have emerged as an excellent class of materials with a unique combination of optoelectronic properties, suitable for a plethora of applications ranging from solar cells to light‐emitting diodes and photoelectrochemical devices. Recent works have showcased hybrid perovskites for electronic applications through improvements in materials design, processing, and device stability. Herein, a comprehensive up‐to‐date review is presented on hybrid perovskite electronics with a focus on transistors and memories. These applications are supported by the fundamental material properties of hybrid perovskite semiconductors such as tunable bandgap, ambipolar charge transport, reasonable mobility, defect characteristics, and solution processability, which are highlighted first. Then, recent progresses on perovskite‐based transistors are reviewed, covering aspects of fabrication process, patterning techniques, contact engineering, 2D versus 3D material selection, and device performance. Furthermore, applications of perovskites in nonvolatile memories and artificial synaptic devices are presented. The ambient instability of hybrid perovskites and the strategies to tackle this bottleneck are also discussed. Finally, an outlook and opportunities to develop perovskite‐based electronics as a competitive and feasible technology are highlighted.
Publisher: Springer Science and Business Media LLC
Date: 29-06-2022
DOI: 10.1038/S43246-022-00261-3
Abstract: Logic gates are fundamental components of integrated circuits, and integration strategies involving multiple logic gates and advanced materials have been developed to meet the development requirements of high-density integrated circuits. However, these strategies are still far from being widely applicable owing to their incompatibility with the modern silicon-based foundry lines. Here, we propose a silicon-foundry-line-based multi-gate one-transistor design to simplify the conventional multi-transistor logic gates into one-transistor gates, thus reducing the circuit footprint by at least 40%. More importantly, the proposed configuration could simultaneously provide the multi-functionalities of logic gates, memory, and artificial synapses. In particular, our design could mimic the artificial synapses in three dimensions while simultaneously being implemented by standard silicon-on-insulator process technology. The foundry-line-compatible one-transistor design has great potential for immediate and widespread applications in next-generation multifunctional electronics.
Publisher: Wiley
Date: 29-10-2020
Publisher: Elsevier BV
Date: 11-2018
Publisher: Springer Science and Business Media LLC
Date: 20-01-2021
DOI: 10.1038/S41467-020-20749-1
Abstract: All-inorganic CsPbI 3 perovskite quantum dots have received substantial research interest for photovoltaic applications because of higher efficiency compared to solar cells using other quantum dots materials and the various exciting properties that perovskites have to offer. These quantum dot devices also exhibit good mechanical stability amongst various thin-film photovoltaic technologies. We demonstrate higher mechanical endurance of quantum dot films compared to bulk thin film and highlight the importance of further research on high-performance and flexible optoelectronic devices using nanoscale grains as an advantage. Specifically, we develop a hybrid interfacial architecture consisting of CsPbI 3 quantum dot/PCBM heterojunction, enabling an energy cascade for efficient charge transfer and mechanical adhesion. The ch ion CsPbI 3 quantum dot solar cell has an efficiency of 15.1% (stabilized power output of 14.61%), which is among the highest report to date. Building on this strategy, we further demonstrate a highest efficiency of 12.3% in flexible quantum dot photovoltaics.
Publisher: Springer Science and Business Media LLC
Date: 29-12-2023
DOI: 10.1007/S40820-022-00983-6
Abstract: Metal halide perovskites have generated significant attention in recent years because of their extraordinary physical properties and photovoltaic performance. Among these, inorganic perovskite quantum dots (QDs) stand out for their prominent merits, such as quantum confinement effects, high photoluminescence quantum yield, and defect-tolerant structures. Additionally, ligand engineering and an all-inorganic composition lead to a robust platform for ambient-stable QD devices. This review presents the state-of-the-art research progress on inorganic perovskite QDs, emphasizing their electronic applications. In detail, the physical properties of inorganic perovskite QDs will be introduced first, followed by a discussion of synthesis methods and growth control. Afterwards, the emerging applications of inorganic perovskite QDs in electronics, including transistors and memories, will be presented. Finally, this review will provide an outlook on potential strategies for advancing inorganic perovskite QD technologies.
Publisher: Elsevier BV
Date: 07-2020
Publisher: Research Square Platform LLC
Date: 06-04-2022
DOI: 10.21203/RS.3.RS-1495375/V1
Abstract: Halide perovskites, due to their remarkable characteristics including high absorption coefficients, tunable bandgaps, superior carrier dynamics, as well as solution-processed procedures, have demonstrated huge potential in next-generation device applications. Creating perovskite heterostructures, featuring the spatial modulation of structural, electronic, and optical properties, is expected to further boost device performance and may even open up new realms however, direct growth of mixed-dimensional lateral heterostructures remains a significant challenge. Here we present a one-pot solution synthesis of two-/three-dimensional (2D/3D) crystalline perovskite lateral heterostructures, leveraging on their different temperature-dependent solubilities. Various types of heterostructures are demonstrated with well-defined interfaces and negligible ion diffusion, exhibiting clear structural and optical modulations. The resultant photodiodes yield a low dark current less than 0.1 nA and a detectivity exceeding 1013 Jones (much higher than those made of 2D or 3D thin crystals). The facile growth of such lateral crystalline perovskite heterostructures underscores a significant advance and opens up new opportunities for advanced perovskite optoelectronics.
Publisher: Royal Society of Chemistry (RSC)
Date: 2023
DOI: 10.1039/D3TA00318C
Abstract: Novel structured thiadiazole-attached carbon nitrides are first synthesized via sintering 5-amino-1,3,4-thiadiazole-2-thiol, demonstrating excellent performances towards photocatalytic H 2 evolution under visible light irradiation.
Publisher: Springer Science and Business Media LLC
Date: 11-05-2020
DOI: 10.1038/S41377-020-0268-1
Abstract: Micro-light-emitting diodes (μ-LEDs) are regarded as the cornerstone of next-generation display technology to meet the personalised demands of advanced applications, such as mobile phones, wearable watches, virtual/augmented reality, micro-projectors and ultrahigh-definition TVs. However, as the LED chip size shrinks to below 20 μm, conventional phosphor colour conversion cannot present sufficient luminance and yield to support high-resolution displays due to the low absorption cross-section. The emergence of quantum dot (QD) materials is expected to fill this gap due to their remarkable photoluminescence, narrow bandwidth emission, colour tuneability, high quantum yield and nanoscale size, providing a powerful full-colour solution for μ-LED displays. Here, we comprehensively review the latest progress concerning the implementation of μ-LEDs and QDs in display technology, including μ-LED design and fabrication, large-scale μ-LED transfer and QD full-colour strategy. Outlooks on QD stability, patterning and deposition and challenges of μ-LED displays are also provided. Finally, we discuss the advanced applications of QD-based μ-LED displays, showing the bright future of this technology.
Publisher: American Chemical Society (ACS)
Date: 27-09-2017
Abstract: Flexible electronics will form the basis of many next-generation technologies, such as wearable devices, biomedical sensors, the Internet of things, and more. However, most flexible devices can bear strains of less than 300% as a result of stretching. In this work, we demonstrate a simple and low-cost paper-based photodetector array featuring superior deformability using printable ZnO nanowires, carbon electrodes, and origami-based techniques. With a folded Miura structure, the paper photodetector array can be oriented in four different directions via tessellated parallelograms to provide the device with excellent omnidirectional light harvesting capabilities. Additionally, we demonstrate that the device can be repeatedly stretched (up to 1000% strain), bent (bending angle ±30°), and twisted (up to 360°) without degrading performance as a result of the paper folding technique, which enables the ZnO nanowire layers to remain rigid even as the device is deformed. The origami-based strategy described herein suggests avenues for the development of next-generation deformable optoelectronic applications.
Publisher: Wiley
Date: 04-12-2021
Abstract: The extraordinary electronic, optical, and mechanical characteristics of 2D materials make them promising candidates for optoelectronics, specifically in infrared (IR) detectors owing to their flexible composition and tunable optoelectronic properties. This review presents the recent progress in IR detectors composed of 2D materials and their hybrid structures, including graphene, black phosphorous, transition metal dichalcogenides, halide perovskite as well as other new layered materials and their heterostructures. The focus is on the short‐wave, mid‐wave, and long‐wave infrared regimes, which pose a grand challenge for rational materials and device designs. The dependence of the device performance on the optical and electronic properties of 2D materials is extensively discussed, aiming to present the general strategies for designing optoelectronic devices with optimal performance. Furthermore, the recent results on 2D material‐based heterostructures are presented with an emphasis on the relationship between band alignment, charge transfer, and IR photodetection. Finally, a summary is given as well as the discussion of existing challenges and future directions.
Publisher: Wiley
Date: 17-04-2021
Publisher: Springer Science and Business Media LLC
Date: 15-11-2018
DOI: 10.1038/S42005-018-0082-8
Abstract: Two dimensional inorganic–organic hybrid perovskites (2D perovskites) suffer from not only quantum confinement, but also dielectric confinement, hindering their application perspective in devices involving the conversion of an optical input into current. In this report, we theoretically predict that an extremely low exciton binding energy can be achieved in 2D perovskites by using high dielectric-constant organic components. We demonstrate that in (HOCH 2 CH 2 NH 3 ) 2 PbI 4 , whose organic material has a high dielectric constant of 37, the dielectric confinement is largely reduced, and the exciton binding energy is 20-times smaller than that in conventional 2D perovskites. As a result, the photo-induced excitons can be thermally dissociated efficiently at room temperature, as clearly indicated from femtosecond transient absorption measurements. In addition, the mobility is largely improved due to the strong screening effect on charge impurities. Such low dielectric-confined 2D perovskites show excellent carrier extraction efficiency, and outstanding humidity resistance compared to conventional 2D perovskites.
Publisher: Wiley
Date: 25-01-2023
Abstract: Solar‐driven photothermal water evaporation is considered an elegant and sustainable technology for freshwater production. The existing systems, however, often suffer from poor stability and biofouling issues, which severely h er their prospects in practical applications. Conventionally, photothermal materials are deposited on the membrane supports via vacuum‐assisted filtration or dip‐coating methods. Nevertheless, the weak inherent material‐membrane interactions frequently lead to poor durability, and the photothermal material layer can be easily peeled off from the hosting substrates or partially dissolved when immersed in water. In the present article, the discovery of the incorporation of borophene into cellulose nanofibers (CNF), enabling excellent environmental stability with a high light‐to‐heat conversion efficiency of 91.5% and water evaporation rate of 1.45 kg m −2 h −1 under simulated sunlight is reported. It is also demonstrated that borophene papers can be employed as an excellent active photothermal material for eliminating almost 100% of both gram‐positive and gram‐negative bacteria within 20 min under three sun irradiations. The result opens a new direction for the design of borophene‐based papers with unique photothermal properties which can be used for the effective treatment of a wide range of wastewaters.
Publisher: American Chemical Society (ACS)
Date: 27-10-2022
Publisher: Wiley
Date: 17-07-2017
Abstract: Organic–inorganic hybrid perovskite materials exhibit a variety of physical properties. Pronounced coupling between phonon, organic cations, and the inorganic framework suggest that these materials exhibit strong light–matter interactions. The photoinduced strain of CH 3 NH 3 PbBr 3 is investigated using high‐resolution and contactless in situ Raman spectroscopy. Under illumination, the material exhibits large blue shifts in its Raman spectra that indicate significant structural deformations (i.e., photostriction). From these shifts, the photostrictive coefficient of CH 3 NH 3 PbBr 3 is calculated as 2.08 × 10 −8 m 2 W −1 at room temperature under visible light illumination. The significant photostriction of CH 3 NH 3 PbBr 3 is attributed to a combination of the photovoltaic effect and translational symmetry loss of the molecular configuration via strong translation–rotation coupling. Unlike CH 3 NH 3 PbI 3 , it is noted that the photostriction of CH 3 NH 3 PbBr 3 is extremely stable, demonstrating no signs of optical decay for at least 30 d. These results suggest the potential of CH 3 NH 3 PbBr 3 for applications in next‐generation optical micro‐electromechanical devices.
Publisher: American Chemical Society (ACS)
Date: 20-06-2023
Publisher: American Chemical Society (ACS)
Date: 15-09-2020
Publisher: IEEE
Date: 03-12-2022
Publisher: Elsevier BV
Date: 09-2018
Publisher: Springer Science and Business Media LLC
Date: 08-01-2021
DOI: 10.1038/S41467-020-20287-W
Abstract: Converting and storing solar energy and releasing it on demand by using solar flow batteries (SFBs) is a promising way to address the challenge of solar intermittency. Although high solar-to-output electricity efficiencies (SOEE) have been recently demonstrated in SFBs, the complex multi-junction photoelectrodes used are not desirable for practical applications. Here, we report an efficient and stable integrated SFB built with back-illuminated single-junction GaAs photoelectrode with an n-p-n sandwiched design. Rational potential matching simulation and operating condition optimization of this GaAs SFB lead to a record SOEE of 15.4% among single-junction SFB devices. Furthermore, the TiO 2 protection layer and robust redox couples in neutral pH electrolyte enable the SFB to achieve stable cycling over 408 h (150 cycles). These results advance the utilization of more practical solar cells with higher photocurrent densities but lower photovoltages for high performance SFBs and pave the way for developing practical and efficient SFBs.
Publisher: Springer Science and Business Media LLC
Date: 11-05-2022
DOI: 10.1038/S41586-022-04588-2
Abstract: The scaling of silicon metal-oxide-semiconductor field-effect transistors has followed Moore's law for decades, but the physical thinning of silicon at sub-ten-nanometre technology nodes introduces issues such as leakage currents
Publisher: Springer Science and Business Media LLC
Date: 16-08-2018
DOI: 10.1038/S41699-018-0070-6
Abstract: Flexible electronics are expected to play a key role in connecting human lives with versatile smart electronic devices due to their adaptability to different shapes, surfaces, and even the human body. However, heat management issues found in most flexible devices due to the low thermal conductivity of conventional plastic or paper substrates become significant for large-scale integration or high-temperature applications. In this study, we employed high thermal conductivity nanopaper composed of two-dimensional (2D) hexagonal boron nitride nanosheets and one-dimensional nanofibrillated cellulose to form a flexible deep-ultraviolet photodetector demonstrating superior photodetectivity of up to 8.05 × 10 10 cm Hz 1/2 /W, a short response time of 0.267 s, and excellent flexible durability featuring repeatable ON/OFF photoswitching over 200 bending cycles. Because the boron nitride paper has a high thermal conductivity of 146 W/mK, which is three orders of magnitude larger than plastic or paper substrates, the photodetectors can work at high temperatures of up to 200 °C. The boron nitride paper-based strategy described herein suggests a path for improving heat dissipation in flexible electronics and achieving high-performance deep-ultraviolet photodetectors, which can be applied in wearable applications.
Publisher: American Chemical Society (ACS)
Date: 06-12-2021
Publisher: Wiley
Date: 28-04-2022
Abstract: Hybrid halide perovskites have emerged as highly promising photovoltaic materials because of their exceptional optoelectronic properties, which are often optimized via compositional engineering like mixing halides. It is well established that hybrid perovskites undergo a series of structural phase transitions as temperature varies. In this work, the authors find that phase transitions are substantially suppressed in mixed‐halide hybrid perovskite single crystals of MAPbI 3‐x Br x (MA = CH 3 NH 3 + and x = 1 or 2) using a complementary suite of diffraction and spectroscopic techniques. Furthermore, as a general behavior, multiple crystallographic phases coexist in mixed‐halide perovskites over a wide temperature range, and a slightly distorted monoclinic phase, hitherto unreported for hybrid perovskites, is dominant at temperatures above 100 K. The anomalous structural evolution is correlated with the glassy behavior of organic cations and optical phonons in mixed‐halide perovskites. This work demonstrates the complex interplay between composition engineering and lattice dynamics in hybrid perovskites, shedding new light on their unique properties.
Publisher: Wiley
Date: 12-01-2021
Publisher: Wiley
Date: 24-07-2020
Publisher: Wiley
Date: 18-11-2019
Abstract: Organic semiconductors demonstrate several advantages over conventional inorganic materials for novel electronic and optoelectronic applications, including molecularly tunable properties, flexibility, low‐cost, and facile device integration. However, before organic semiconductors can be used for the next‐generation devices, such as ultrafast photodetectors (PDs), it is necessary to develop new materials that feature both high mobility and ambient stability. Toward this goal, a highly stable PD based on the organic single crystal [PtBr 2 (5,5′‐bis(CF 3 CH 2 OCH 2 )‐2,2′‐bpy)] (or “Pt complex (1o)”) is demonstrated as the active semiconductor channel—a material that features a lamellar molecular structure and high‐quality, intraligand charge transfer. Benefitting from its unique crystal structure, the Pt‐complex (1o) device exhibits a field‐effect mobility of ≈0.45 cm 2 V −1 s −1 without loss of significant performance under ambient conditions even after 40 days without encapsulation, as well as immersion in distilled water for a period of 24 h. Furthermore, the device features a maximum photoresponsivity of 1 × 10 3 A W −1 , a detectivity of 1.1 × 10 12 cm Hz 1/2 W −1 , and a record fast response/recovery time of 80/90 µs, which has never been previously achieved in other organic PDs. These findings strongly support and promote the use of the single‐crystal Pt complex (1o) in next‐generation organic optoelectronic devices.
Publisher: Wiley
Date: 20-09-2020
Publisher: Wiley
Date: 24-04-2019
Publisher: American Chemical Society (ACS)
Date: 31-12-2018
Abstract: 3D organic-inorganic hybrid halide perovskites have attracted great interest due to their impressive optoelectronic properties. Recently, the emergence of 2D layered hybrid perovskites, with their excellent and tunable optoelectronic behavior, has encouraged researchers to develop the next generation of optoelectronics based on these 2D materials. However, device fabrication methods of scalable patterning on both types of hybrid perovskites are still lacking as these materials are readily damaged by the organic solvents in standard lithographic processes. We conceived the orthogonal processing and patterning method: Chlorobenzene and hexane, which are orthogonal to hybrid perovskites, are utilized in modified electron beam lithography (EBL) processes to fabricate perovskite-based devices without compromising their electronic or optical characteristics. As a proof-of-concept, we used the orthogonal EBL technique to fabricate a 2D layered single-crystal (C
Publisher: Wiley
Date: 29-10-2019
Publisher: Wiley
Date: 05-01-2022
Abstract: Integrating multiple semiconductors with distinct physical properties is a practical design strategy for realizing novel optoelectronic devices with unprecedented functionalities. In this work, a photonic resistive switching (RS) memory is demonstrated based on solution‐processed bilayers of strontium titanate (SrTiO 3 or STO) quantum dots (QDs) and all‐inorganic halide perovskite CsPbBr 3 (CPB) with an Ag/STO/CPB/Au architecture. Compared with the single‐layer STO or CPB RS device, the double‐layer device shows considerably improved RS performance with a high switching ratio over 10 5 , an endurance of 3000 cycles, and a retention time longer than 2 × 10 4 s. The formation of heterojunction between STO and CPB significantly enhances the high resistance state, and the separation of the active silver electrode and the CPB layer contributes to the long‐term stability. More importantly, the photonic RS device exhibits UV–visible dual‐band response due to the photogating effect and the light‐induced modification of the heterojunction barrier. Last, tri‐mode operation, i.e., photodetector, memory, and photomemory, is demonstrated via tailoring the light and electric stimuli. This bilayer device architecture provides a unique approach toward enhancing the performance of photoresponsive data‐storage devices.
Publisher: Royal Society of Chemistry (RSC)
Date: 2020
DOI: 10.1039/C9MH01788G
Abstract: Organic intercalation engineering of perovskites endows the as-constructed quasi-2D Dion–Jacobson α-CsPbI 3 with a linearly aligned bandgap and fundamentally enhanced stability.
Publisher: Research Square Platform LLC
Date: 30-07-2020
DOI: 10.21203/RS.3.RS-47321/V1
Abstract: All-inorganic CsPbI3 perovskite quantum dots (QDs) have received intense research interest for photovoltaic applications because of the recently demonstrated higher power conversion efficiency compared to solar cells using other QD materials. These QD devices also exhibit good mechanical stability amongst various thin-film photovoltaic technologies. In this work, through developing a hybrid interfacial architecture consisting of CsPbI3 QD/PCBM heterojunctions, we report the formation of an energy cascade for efficient charge transfer at both QD heterointerfaces and QD/electron transport layer interfaces. The ch ion CsPbI3 QD solar cell has a best power conversion efficiency of 15.1%, which is among the highest report to date. Building on this strategy, we demonstrate the very first perovskite QD flexible solar cell with a record efficiency of 12.3%. A detailed morphological characterization reveals that the perovskite QD film can better retain structure integrity than perovskite bulk thin-film under external mechanical stress. This work is the first to demonstrate higher mechanical endurance of QD film compared to bulk thin-film, and highlights the importance of further research on high‐performance and flexible optoelectronic devices using solution-processed QDs.
Publisher: Wiley
Date: 21-07-2020
Publisher: Wiley
Date: 02-06-2020
Publisher: Wiley
Date: 21-08-2022
Abstract: Metal‐halide perovskites have drawn profuse attention during the past decade, owing to their excellent electrical and optical properties, facile synthesis, efficient energy conversion, and so on. Meanwhile, the development of information storage technologies and digital communications has fueled the demand for novel semiconductor materials. Low‐dimensional perovskites have offered a new force to propel the developments of the memory field due to the excellent physical and electrical properties associated with the reduced dimensionality. In this review, the mechanisms, properties, as well as stability and performance of low‐dimensional perovskite memories, involving both molecular‐level perovskites and structure‐level nanostructures, are comprehensively reviewed. The property–performance correlation is discussed in‐depth, aiming to present effective strategies for designing memory devices based on this new class of high‐performance materials. Finally, the existing challenges and future opportunities are presented.
Publisher: American Chemical Society (ACS)
Date: 24-04-2022
Abstract: Vanadium dioxide (VO
Publisher: American Chemical Society (ACS)
Date: 29-09-2020
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 12-2015
Publisher: Wiley
Date: 06-02-2020
Publisher: American Chemical Society (ACS)
Date: 02-04-2021
Publisher: Wiley
Date: 19-02-2020
Publisher: American Chemical Society (ACS)
Date: 04-2021
Publisher: American Chemical Society (ACS)
Date: 03-04-2020
Publisher: American Chemical Society (ACS)
Date: 18-09-2020
Publisher: Springer Science and Business Media LLC
Date: 2022
DOI: 10.1038/S41377-021-00686-4
Abstract: Neuromorphic vision sensors have been extremely beneficial in developing energy-efficient intelligent systems for robotics and privacy-preserving security applications. There is a dire need for devices to mimic the retina’s photoreceptors that encode the light illumination into a sequence of spikes to develop such sensors. Herein, we develop a hybrid perovskite-based flexible photoreceptor whose capacitance changes proportionally to the light intensity mimicking the retina’s rod cells, paving the way for developing an efficient artificial retina network. The proposed device constitutes a hybrid nanocomposite of perovskites (methyl-ammonium lead bromide) and the ferroelectric terpolymer (polyvinylidene fluoride trifluoroethylene-chlorofluoroethylene). A metal-insulator-metal type capacitor with the prepared composite exhibits the unique and photosensitive capacitive behavior at various light intensities in the visible light spectrum. The proposed photoreceptor mimics the spectral sensitivity curve of human photopic vision. The hybrid nanocomposite is stable in ambient air for 129 weeks, with no observable degradation of the composite due to the encapsulation of hybrid perovskites in the hydrophobic polymer. The functionality of the proposed photoreceptor to recognize handwritten digits (MNIST) dataset using an unsupervised trained spiking neural network with 72.05% recognition accuracy is demonstrated. This demonstration proves the potential of the proposed sensor for neuromorphic vision applications.
Publisher: Optica Publishing Group
Date: 30-10-2020
DOI: 10.1364/PRJ.402411
Abstract: Halide perovskites, such as methylammonium lead halide perovskites ( MAPbX 3 , X = I , Br, and Cl), are emerging as promising candidates for a wide range of optoelectronic applications, including solar cells, light-emitting diodes, and photodetectors, due to their superior optoelectronic properties. All-inorganic lead halide perovskites CsPbX 3 are attracting a lot of attention because replacing the organic cations with Cs + enhances the stability, and its halide-mixing derivatives offer broad bandgap tunability covering nearly the entire visible spectrum. However, there is evidence suggesting that the optical properties of mixed-halide perovskites are influenced by phase segregation under external stimuli, especially illumination, which may negatively impact the performance of optoelectronic devices. It is reported that the mixed-halide perovskites in forms of thin films and nanocrystals are segregated into a low-bandgap I-rich phase and a high-bandgap Br-rich phase. Herein, we present a critical review on the synthesis and basic properties of all-inorganic perovskites, phase-segregation phenomena, plausible mechanisms, and methods to mitigate phase segregation, providing insights on advancing mixed-halide perovskite optoelectronics with reliable performance.
Publisher: Optica Publishing Group
Date: 10-11-2021
DOI: 10.1364/PRJ.434270
Abstract: We propose a flexible white-light system for high-speed visible-light communication (VLC) applications, which consists of a semipolar blue InGaN/GaN single-quantum-well micro-light-emitting diode (LED) on a flexible substrate pumping green CsPbBr 3 perovskite quantum-dot (PQD) paper in nanostructure form and red CdSe QD paper. The highest bandwidth for CsPbBr 3 PQD paper, 229 MHz, is achieved with a blue micro-LED pumping source and a high data transmission rate of 400 Mbps this is very promising for VLC application. An 817 MHz maximum bandwidth and a 1.5 Gbps transmission speed are attained by the proposed semipolar blue micro-LEDs. The proposed flexible white light system and the high-bandwidth PQD paper could pave the way for VLC wearable devices.
Publisher: Springer Science and Business Media LLC
Date: 24-02-2023
DOI: 10.1038/S41427-023-00465-0
Abstract: Metal halide perovskites can be readily synthesized, they exhibit tunable physical properties and excellent performance, and they are heavily studied optoelectronic materials. Compared to the typical three-dimensional perovskites, morphological-level one-dimensional (1D) nanostructures enable charge transport and photon propagation with low exciton binding energies and long charge-carrier diffusion lengths, while molecular-level 1D nanostructures exhibit good compositional and structural flexibilities, highly tunable bandgaps, strong quantum confinement effects, and excellent ambient stabilities. The 1D natures of these emerging halide perovskites enhance the performance of optoelectronic devices. Herein, we highlight recent progress realized in the syntheses and characterizations of both morphological- and molecular-level 1D halide perovskites with tunable structures, compositions, and properties, as well as their photovoltaic, light-emission, and photodetection applications. In addition, current challenges, future prospects, and promising research directions are discussed to provide guidance in advancing the field of 1D perovskites.
Publisher: Wiley
Date: 16-11-2022
Abstract: In spite of the merits such as Earth abundance and high performance, Cu 2 ZnSn(S,Se) 4 (CZTSSe) solar cells suffer from unfavorable Sn Zn antisite defects and complexes, which act as nonradiative recombination centers and deteriorate the open‐circuit voltage ( V OC ). Therefore, the management of Sn composition is the prerequisite for achieving high‐efficiency CZTSSe photovoltaic devices. At present, the Sn‐related composition and defect modifications at different selenization pressures remain unclear, which restrain the development of efficient kesterite solar cells. Herein, a facile yet effective strategy to accurately adjust the Sn content in CZTSSe films by simply optimizing the selenization pressure is demonstrated. Compared with the widely used atmospheric pressure, it is unveiled that the appropriate negative pressure (0.7 atm) can tailor the optimal Sn content in the absorber layer, influencing both the Sn‐related defects and the microstructures. In contrast, a lower (0.4 atm) and a higher (1.3 atm) selenization pressure results in undesirable deep Cu Sn defects and a Sn(S,Se) 2 secondary phase, respectively. A ch ion device fabricated at this optimal selenization pressure (0.7 atm) exhibits a power conversion efficiency of 11.32% with a V OC of 0.496 V. This study paves the path toward highly efficient kesterite solar cells by tailoring the composition‐dependent defects.
Publisher: Wiley
Date: 11-03-2022
Abstract: Contact engineering is a prerequisite for achieving desirable functionality and performance of semiconductor electronics, which is particularly critical for organic–inorganic hybrid halide perovskites due to their ionic nature and highly reactive interfaces. Although the interfaces between perovskites and charge‐transporting layers have attracted lots of attention due to the photovoltaic and light‐emitting diode applications, achieving reliable perovskite/electrode contacts for electronic devices, such as transistors and memories, remains as a bottleneck. Herein, a critical review on the elusive nature of perovskite/electrode interfaces with a focus on the interfacial electrochemistry effects is presented. The basic guidelines of electrode selection are given for establishing non‐polarized interfaces and optimal energy level alignment for perovskite materials. Furthermore, state‐of‐the‐art strategies on interface‐related electrode engineering are reviewed and discussed, which aim at achieving ohmic transport and eliminating hysteresis in perovskite devices. The role and multiple functionalities of self‐assembled monolayers that offer a unique approach toward improving perovskite/electrode contacts are also discussed. The insights on electrode engineering pave the way to advancing stable and reliable perovskite devices in erse electronic applications.
Publisher: AIP Publishing
Date: 15-07-2020
DOI: 10.1063/5.0009713
Abstract: Artificial iconic memories, also called photomemories, are new types of nonvolatile memory that can simultaneously detect and store light information in a monolithic device. Several approaches have been proposed to construct artificial iconic memories, such as three-terminal field effect transistors, which can achieve an effective control of the gate voltage and external light terminals. The drawbacks in constructing these memories involve complicated fabrication processes, and the resulting performance of, for ex le, perovskite transistor-type photomemories is limited by the low carrier mobilities and poor ambient stabilities, whereas architectures based on floating gate modulations entail strict interface engineering and poor device reliability. In this paper, we propose a novel monolithic artificial iconic memory with a multilayer architecture of indium tin oxide erovskite/gold erovskite/silver, which combines the memory and photodetector functionalities of perovskites in an integrated device. The bottom perovskite layer plays the role of a photodetector, modulating the voltage bias on the top perovskite layer that serves as a resistive switching memory. This multilayer perovskite device can store photo-sensing data in its resistive states, with a memory retention of 5 × 103 s and ambient stability longer than sixty days. As a prototype demonstration, a 7 × 7 artificial iconic memory array is constructed to detect and store data on light intensity distribution, enabling a nonvolatile imaging functionality. Our work provides a new platform for designing perovskite-based architectures with simultaneous light detection and data storage capabilities.
Publisher: Elsevier BV
Date: 04-2020
Publisher: AIP Publishing
Date: 26-09-2016
DOI: 10.1063/1.4963671
Abstract: The surface effects of ZnO-based resistive random-access memory (ReRAM) were investigated using various electrodes. Pt electrodes were found to have better performance in terms of the device's switching functionality. A thermodynamic model of the oxygen chemisorption process was proposed to explain this electrode-dependent switching behavior. The temperature-dependent switching voltage demonstrates that the ReRAM devices fabricated with Pt electrodes have a lower activation energy for the chemisorption process, resulting in a better resistive switching performance. These findings provide an in-depth understanding of electrode-dependent switching behaviors and can serve as design guidelines for future ReRAM devices.
Publisher: Wiley
Date: 17-06-2023
Abstract: Gas sensors are of great interest to portable and miniaturized sensing technologies with applications ranging from air quality monitoring to explosive detection and medical diagnostics, but the existing chemiresistive NO 2 sensors still suffer from issues such as poor sensitivity, high operating temperature, and slow recovery. Herein, a high‐performance NO 2 sensors based on all‐inorganic perovskite nanocrystals (PNCs) is reported, achieving room temperature operation with ultra‐fast response and recovery time. After tailoring the halide composition, superior sensitivity of ≈67 at 8 ppm NO 2 is obtained in CsPbI 2 Br PNC sensors with a detection level down to 2 ppb, which outperforms other nanomaterial‐based NO 2 sensors. Furthermore, the remarkable optoelectronic properties of such PNCs enable dual‐mode operation, i.e., chemiresistive and chemioptical sensing, presenting a new and versatile platform for advancing high‐performance, point‐of‐care NO 2 detection technologies.
Publisher: Wiley
Date: 29-11-2022
Abstract: Structural defects are ubiquitous for polycrystalline perovskite films, compromising device performance and stability. Herein, a universal method is developed to overcome this issue by incorporating halide perovskite quantum dots (QDs) into perovskite polycrystalline films. CsPbBr 3 QDs are deposited on four types of halide perovskite films (CsPbBr 3 , CsPbIBr 2 , CsPbBrI 2 , and MAPbI 3 ) and the interactions are triggered by annealing. The ions in the CsPbBr 3 QDs are released into the thin films to passivate defects, and concurrently the hydrophobic ligands of QDs self‐assemble on the film surfaces and grain boundaries to reduce the defect density and enhance the film stability. For all QD‐treated films, PL emission intensity and carrier lifetime are significantly improved, and surface morphology and composition uniformity are also optimized. Furthermore, after the QD treatment, light‐induced phase segregation and degradation in mixed‐halide perovskite films are suppressed, and the efficiency of mixed‐halide CsPbIBr 2 solar cells is remarkably improved to over 11% from 8.7%. Overall, this work provides a general approach to achieving high‐quality halide perovskite films with suppressed phase segregation, reduced defects, and enhanced stability for optoelectronic applications.
Publisher: Wiley
Date: 29-04-2020
Publisher: Springer Science and Business Media LLC
Date: 06-08-2020
DOI: 10.1038/S41467-020-17660-0
Abstract: Converting sunlight into a storable form of energy by spontaneous water splitting is of great interest but the difficulty in simultaneous management of optical, electrical, and catalytic properties has limited the efficiency of photoelectrochemical (PEC) devices. Herein, we implemented a decoupling scheme of light harvesting and electrocatalysis by employing a back-buried junction (BBJ) PEC cell design, which enables % front side light-harvesting, whereas the electrochemical reaction in conjunction with carrier separation/transport/collection occurs on the back side of the PEC cell. The resultant silicon BBJ-PEC half-cell produces a current density of 40.51 mA cm −2 for hydrogen evolution by minimizing optical, electrical, and catalytic losses (as low as 6.11, 1.76, and 1.67 mA cm −2 , respectively). Monolithic fabrication also enables three BBJ-PEC cells to be connected in series as a single module, enabling unassisted solar water-splitting with a solar-to-hydrogen conversion efficiency of 15.62% and a hydrogen generation rate of 240 μg cm −2 h −1 .
Location: Saudi Arabia
Start Date: 2024
End Date: 12-2026
Amount: $461,000.00
Funder: Australian Research Council
View Funded Activity