ORCID Profile
0000-0002-2582-1740
Current Organisation
Linköping University
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Publisher: American Chemical Society (ACS)
Date: 17-06-2021
Publisher: Royal Society of Chemistry (RSC)
Date: 2014
DOI: 10.1039/C4TA02515F
Abstract: Ternary blends of C 60 , C 70 and a thiophene–quinoxaline copolymer (TQ1) can be readily processed from solution. A solar cell efficiency of 3.6% is achieved with a 2 : 1 : 1 TQ1:C 60 :C 70 mixture, accompanied by a high internal quantum efficiency of 75%.
Publisher: Wiley
Date: 11-03-2011
Publisher: IOP Publishing
Date: 17-09-2010
DOI: 10.1088/0953-8984/22/39/395009
Abstract: Surface states in ZnO nanoparticles play an important role in controlling their electrical transport properties, and these properties can be modified greatly by exposure to UV light. In order to investigate the origin of these effects, we investigate the change in the optical absorption of films of ZnO nanoparticles on exposure to UV light. The modulation spectrum changes from the first derivative to the second derivative of the absorption spectrum as the films are annealed. UV illumination changes the surface states of the nanocrystals, leading to a change in the electric field within the films, which we study using electrostatic force microscopy. The modulation of the optical absorption is found to be consistent with a Stark effect caused by the change in the electric field.
Publisher: Elsevier BV
Date: 12-2020
Publisher: Springer Science and Business Media LLC
Date: 10-08-2021
DOI: 10.1038/S41467-021-25092-7
Abstract: Molecular additives are widely utilized to minimize non-radiative recombination in metal halide perovskite emitters due to their passivation effects from chemical bonds with ionic defects. However, a general and puzzling observation that can hardly be rationalized by passivation alone is that most of the molecular additives enabling high-efficiency perovskite light-emitting diodes (PeLEDs) are chelating (multidentate) molecules, while their respective monodentate counterparts receive limited attention. Here, we reveal the largely ignored yet critical role of the chelate effect on governing crystallization dynamics of perovskite emitters and mitigating trap-mediated non-radiative losses. Specifically, we discover that the chelate effect enhances lead-additive coordination affinity, enabling the formation of thermodynamically stable intermediate phases and inhibiting halide coordination-driven perovskite nucleation. The retarded perovskite nucleation and crystal growth are key to high crystal quality and thus efficient electroluminescence. Our work elucidates the full effects of molecular additives on PeLEDs by uncovering the chelate effect as an important feature within perovskite crystallization. As such, we open new prospects for the rationalized screening of highly effective molecular additives.
Publisher: American Chemical Society (ACS)
Date: 07-06-2019
Abstract: Organic solar cells are thought to suffer from poor thermal stability of the active layer nanostructure, a common belief that is based on the extensive work that has been carried out on fullerene-based systems. We show that a widely studied non-fullerene acceptor, the indacenodithienothiophene-based acceptor ITIC, crystallizes in a profoundly different way as compared to fullerenes. Although fullerenes are frozen below the glass-transition temperature T
Publisher: American Association for the Advancement of Science (AAAS)
Date: 06-11-2020
Abstract: Alloying magnetic ions into halide double perovskites brings new opportunities for spintronics.
Publisher: American Chemical Society (ACS)
Date: 06-08-2014
DOI: 10.1021/JA5051692
Abstract: A new tetracyclic lactam building block for polymer semiconductors is reported that was designed to combine the many favorable properties that larger fused and/or amide-containing building blocks can induce, including improved solid-state packing, high charge carrier mobility, and improved charge separation. Copolymerization with thiophene resulted in a semicrystalline conjugated polymer, PTNT, with a broad bandgap of 2.2 eV. Grazing incidence wide-angle X-ray scattering of PTNT thin films revealed a strong tendency for face-on π-stacking of the polymer backbone, which was retained in PTNT:fullerene blends. Corresponding solar cells featured a high open-circuit voltage of 0.9 V, a fill factor around 0.6, and a power conversion efficiency as high as 5% for >200 nm thick active layers, regardless of variations in blend stoichiometry and nanostructure. Moreover, efficiencies of >4% could be retained when thick active layers of ∼400 nm were employed. Overall, these values are the highest reported for a conjugated polymer with such a broad bandgap and are unprecedented in materials for tandem and particularly ternary blend photovoltaics. Hence, the newly developed tetracyclic lactam unit has significant potential as a conjugated building block in future organic electronic materials.
Publisher: Springer Science and Business Media LLC
Date: 04-02-2019
DOI: 10.1038/S41467-019-08386-9
Abstract: Despite significant development recently, improving the power conversion efficiency of organic photovoltaics (OPVs) is still an ongoing challenge to overcome. One of the prerequisites to achieving this goal is to enable efficient charge separation and small voltage losses at the same time. In this work, a facile synthetic strategy is reported, where optoelectronic properties are delicately tuned by the introduction of electron-deficient-core-based fused structure into non-fullerene acceptors. Both devices exhibited a low voltage loss of 0.57 V and high short-circuit current density of 22.0 mA cm −2 , resulting in high power conversion efficiencies of over 13.4%. These unconventional electron-deficient-core-based non-fullerene acceptors with near-infrared absorption lead to low non-radiative recombination losses in the resulting organic photovoltaics, contributing to a certified high power conversion efficiency of 12.6%.
Publisher: Royal Society of Chemistry (RSC)
Date: 2016
DOI: 10.1039/C6TA00531D
Abstract: Thermal annealing on TQ1:N2200 all-polymer solar cells leads to higher photocurrent, fill factor, and almost doubled efficiency. Current maps from conductive-AFM are shown.
Publisher: American Chemical Society (ACS)
Date: 18-03-2014
DOI: 10.1021/NN501185H
Abstract: We investigate the loss mechanisms in hybrid photovoltaics based on blends of poly(3-hexylthiophene) with CdSe nanocrystals of various sizes. By combining the spectroscopic and electrical measurements on working devices as well as films, we identify that high trap-mediated recombination is responsible for the loss of photogenerated charge carriers in devices with small nanocrystals. In addition, we demonstrate that the reduced open-circuit voltage for devices with small nanocrystals is also caused by the traps.
Publisher: American Association for the Advancement of Science (AAAS)
Date: 03-07-2020
Abstract: Ionic liquids have been shown to stabilize organic-inorganic perovskite solar cells with metal oxide carrier-transport layers, but they are incompatible with more readily processible organic analogs. Lin et al. found that an ionic solid, a piperidinium salt, enhanced the efficiency of positive-intrinsic-negative layered perovskite solar cells with organic electron and hole extraction layers. Aggressive aging testing showed that this additive retarded segregation into impurity phases and pinhole formation in the perovskite layer. Science , this issue p. 96
Publisher: Wiley
Date: 10-11-2016
Abstract: Five polymer donors with distinct chemical structures and different electronic properties are surveyed in a planar and narrow-bandgap fused-ring electron acceptor (IDIC)-based organic solar cells, which exhibit power conversion efficiencies of up to 11%.
Location: United Kingdom of Great Britain and Northern Ireland
Location: United Kingdom of Great Britain and Northern Ireland
No related grants have been discovered for Feng Gao.