ORCID Profile
0000-0001-5489-6090
Current Organisations
James Cook University
,
Australian National University
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Publisher: Royal Society of Chemistry (RSC)
Date: 2017
DOI: 10.1039/C6RA26178G
Abstract: A series of three benzothiadiazole-indacenodithieno[3,2- b ]thiophene (BT–IDTT) based ladder-type polymers containing the acceptor ( P1 ) or donor moieties ( P2 and P3 ) are reported for ambipolar OFETs and complementary inverters.
Publisher: Wiley
Date: 16-03-2022
Abstract: A key limitation in perovskite solar cell (PSC) performance is suboptimal electronic properties at the perovskite–transport layer (TL) interfaces, which result in parasitic nonradiative recombination. Interface recombination depends on the concentration of recombination‐active defects, but as a recombination event requires both an electron and a hole, the magnitude and sign of charge accumulation at the perovskite–TL heterojunctions are also critical. Here, we employ a well‐established numerical ion‐electron drift‐diffusion model of PSCs to illustrate how the work function of the transport layer is an important factor in determining the total recombination activity at the perovskite interfaces. We show that the equilibrium electrostatics of the perovskite–TL heterojunctions, which are determined by the work function difference between the two materials, can result in increased recombination rates for any given concentration of interface defects. As a case study, we compare PSCs incorporating a NiO X hole transport layer with those with a spiro‐OMeTAD. We show that the work function of NiO X can induce greater electron accumulation at the perovskite–NiO X interface, which leads to increased interface recombination. Finally, a higher ion concentration is found to be beneficial to overall device performance by displacing accumulated electrons or holes at the TL interfaces and thus reducing recombination rates.
Publisher: Elsevier BV
Date: 2018
Publisher: American Chemical Society (ACS)
Date: 15-02-2017
Abstract: Understanding the sensing mechanism in organic chemical sensors is essential for improving the sensing performance such as detection limit, sensitivity, and other response/recovery time, selectivity, and reversibility for real applications. Here, we report a highly sensitive printed ammonia (NH
Publisher: American Chemical Society (ACS)
Date: 25-04-2019
Abstract: We report on systematic mobility enhancements in electrolyte-gated organic field-effect transistors (OFETs) by thinning down the active layer and exploiting polymer solid-state electrolyte gate insulators (SEGIs). The SEGI is composed of homogeneous poly(vinylidene fluoride- co-hexafluoropropylene) [P(VDF-HFP)] polymer solution-ion gel blends of high areal capacitance of >10 μF cm
Publisher: Elsevier BV
Date: 10-2022
Publisher: Royal Society of Chemistry (RSC)
Date: 2021
DOI: 10.1039/D1TC90006D
Abstract: Correction for ‘High-capacitance polyurethane ionogels for low-voltage operated organic transistors and pressure sensors’ by Grace Dansoa Tabi et al. , J. Mater. Chem. C , 2020, 8 , 17107–17113, DOI: 10.1039/D0TC02364G.
Publisher: Elsevier BV
Date: 03-2022
Publisher: Elsevier BV
Date: 03-2018
Publisher: Elsevier BV
Date: 04-2018
Publisher: Springer Science and Business Media LLC
Date: 12-2020
Publisher: Elsevier BV
Date: 04-2023
Publisher: Wiley
Date: 11-08-2021
Abstract: Dimensional engineering of perovskite films is a promising pathway to improve the efficiency and stability of perovskite solar cells (PSCs). In this context, surface or bulk passivation of defects in 3D perovskite film by careful introduction of 2D perovskite plays a key role. Here the authors demonstrate a 2D perovskite passivation scheme based on octylammonium chloride, and show that it provides both bulk and surface passivation of 1.6 eV bandgap 3D perovskite film for highly efficient (≈23.62%) PSCs with open‐circuit voltages up to 1.24 V. Surface and depth‐resolved microscopy and spectroscopy analysis reveal that the Cl − anion diffuses into the perovskite bulk, passivating defects, while the octylammonium ligands provide effective, localized surface passivation. The authors find that the Cl − diffusion into the perovskite lattice is independent of the 2D perovskite crystallization process and occurs rapidly during deposition of the 2D precursor solution. The annealing‐induced evaporation of Cl from bulk perovskite is also inhibited in 2D–3D perovskite film as compared to pristine 3D perovskite, ensuring effective bulk passivation in the relevant film.
Publisher: Wiley
Date: 31-03-2021
Abstract: Perovskite solar cells are a potential game changer for the photovoltaics industry, courtesy of their facile fabrication and high efficiency. Despite this, commercialization is being held back by poor stability. To become economically feasible for commercial production, perovskite solar cells must meet or exceed industry standards for operational lifetime and reliability. In this regard, mixed dimensional 2D‐3D perovskite solar cells, incorporating long carbon‐chain organic spacer cations, have shown promising results, with enhancement in both device efficiency and stability. Dimensional engineering of perovskite films requires a delicate balance of 2D and 3D perovskite composition to take advantage of the specific properties of each material phase. This review summarizes and assesses the current understanding, and apparent contradictions in the state‐of‐the‐art mixed dimensional perovskite solar cell literature regarding the origin of stability and performance enhancement. By combining and comparing results from experimental and theoretical studies it is focused on how the perovskite composition, film formation methods, additive and solvent engineering influence efficiency and stability, and identify future research directions to further improve both key performance metrics.
Publisher: Wiley
Date: 17-11-2020
Abstract: Dimensional engineering of perovskite solar cells has attracted significant research attention recently because of the potential to improve both device performance and stability. Here, a novel 2D passivation scheme for 3D perovskite solar cells is demonstrated using a mixed cation composition of 2D perovskite based on two different isomers of butylammonium iodide. The dual‐cation 2D perovskite outperforms its single cation 2D counterparts in surface passivation quality, resulting in devices with an impressive open‐circuit voltage of 1.21 V for a perovskite composition with an optical bandgap of ≈1.6 eV, and a ch ion efficiency of 23.27%. Using a combination of surface elemental analysis and valence electron spectra decomposition, it is shown that an in situ interaction between the 2D perovskite precursor and the 3D active layer results in surface intermixing of 3D and 2D perovskite phases, providing an effective combination of defect passivation and enhanced charge transfer, despite the semi‐insulating nature of the 2D perovskite phase. The demonstration of the synergistic interaction of multiple organic spacer cations in a 2D passivation layer offers new opportunities for further enhancement of device performance with mixed dimensional perovskite solar cells.
Publisher: Wiley
Date: 08-07-2020
Publisher: Elsevier BV
Date: 12-2019
Publisher: Wiley
Date: 10-01-2023
Abstract: Methylammonium (MA)‐free perovskite solar cells have the potential for better thermal stability than their MA‐containing counterparts. However, the efficiency of MA‐free perovskite solar cells lags behind due to inferior bulk quality. In this work, 4‐methylphenethylammonium chloride (4M‐PEACl) is added into a MA‐free perovskite precursor, which results in greatly enhanced bulk quality. The perovskite crystal grains are significantly enlarged, and defects are suppressed by a factor of four upon the incorporation of an optimal concentration of 4M‐PEACl. Quasi‐2D perovskites are formed and passivate defects at the grain boundaries of the perovskite crystals. Furthermore, the perovskite surface chemistry is modified, resulting in surface energies more favorable for hole extraction. This facile approach leads to a steady state efficiency of 23.7% (24.2% in reverse scan, 23.0% in forward scan) for MA‐free perovskite solar cells. The devices also show excellent light stability, retaining more than 93% of the initial efficiency after 1000 h of constant illumination in a nitrogen environment. In addition, a four‐terminal mechanically stacked perovskite‐silicon tandem solar cell with ch ion efficiency of 30.3% is obtained using this MA‐free composition. The encapsulated tandem devices show excellent operational stability, retaining more than 98% of the initial performance after 42 day/night cycles in an ambient atmosphere.
Publisher: Wiley
Date: 26-05-2022
Abstract: One of the important factors in the performance of perovskite solar cells (PSCs) is effective defect passivation. Dimensional engineering technique is a promising method to efficiently passivate non‐radiative recombination pathways in the bulk and surface of PSCs. Herein, a passivation approach for the perovskite/hole transport layer interface is presented, using a mixture of guanidinium and n‐octylammonium cations introduced via GuaBr and n‐OABr. The dual‐cation passivation layer can provide an open‐circuit voltage of 1.21 V with a power conversion efficiency of 23.13%, which is superior to their single cation counterparts. The mixed‐cation passivation layer forms a 1D/2D perovskite film on top of 3D perovskite, leading to a more hydrophobic and smoother surface than the uncoated film. A smooth surface can diminish non‐radiative recombination and enhance charge extraction at the interface making a better contact with the transport layer, resulting in improved short‐circuit current. In addition, space charge‐limited current measurements show a three times reduction in the trap‐filled limit voltage in the mixed‐cation passivated s le compared with unpassivated cells, indicating fewer trapped states. The shelf‐life stability test in ambient atmosphere with 60% relative humidity as well as light‐soaking stability reveal the highest stability for the dual‐cation surface passivation.
Publisher: Royal Society of Chemistry (RSC)
Date: 2020
DOI: 10.1039/D0TC02364G
Abstract: A facile method to fabricate high-capacitance stretchable polyurethane ionogels is reported for organic transistor and pressure sensor applications, measuring remarkable mobility of ∼2 cm 2 V −1 s −1 and a high-pressure sensitivity of 0.12 kPa −1 .
Publisher: Wiley
Date: 05-10-2022
DOI: 10.1002/GDJ3.180
Abstract: We provide a 1‐year dataset of atmospheric surface CO 2 , CH 4 and H 2 O concentrations and δ 13 C‐CO 2 values from an Australian savanna site. These semi‐arid ecosystems act as carbon sinks in wet years but the persistence of the sink in dry years is uncertain. The dataset can be used to constrain uncertainties in modelling of greenhouse gas budgets, improve algorithms for satellite measurements and characterize the role of vegetation and soil in modulating atmospheric CO 2 concentrations. We found pronounced seasonal variations in daily mean CO 2 concentrations with an increase (by 5–7 ppmv) after the first rainfall of the wet season in early December with peak concentrations maintained until late January. The CO 2 increase reflected the initiation of rapid microbial respiration from soil and vegetation sources upon initial wetting. As the wet season progressed, daily CO 2 concentrations were variable, but generally decreased back to dry season levels as CO 2 assimilation by photosynthesis increased. Mean daily concentrations of CH 4 increased in the wet season by up to 0.2 ppmv relative to dry season levels as the soil profile became waterlogged after heavy rainfall events. During the dry season there was regular cycling between maximum CO 2 /minimum δ 13 C‐CO 2 at night and minimum CO 2 /maximum δ 13 C‐CO 2 during the day. In the wet season diel patterns were less regular in response to variable cloud cover and rainfall. CO 2 isotope data showed that in the wet season, surface CO 2 was predominantly a two‐component mixture influenced by C 3 plant assimilation (day) and soil lant respiration (night), while regional background air from higher altitudes represented an additional CO 2 source in the dry season. Higher wind speeds during the dry season increased vertical mixing compared to the wet season. In addition, night‐time advection of high‐altitude air during low temperature conditions also promoted mixing in the dry season.
Publisher: Wiley
Date: 15-02-2017
Abstract: A new concept of a high-capacitance polymeric dielectric based on high-k polymer and ion gel blends is reported. This solid-state electrolyte gate insulator enables remarkable field-effect mobilities exceeding 10 cm
Publisher: American Chemical Society (ACS)
Date: 19-06-2017
No related grants have been discovered for Grace Tabi.