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The impact of light on the Schottky barrier height (SBH) in p-type graphene/n-type Si (p-Gr/n-Si) based near-infrared photodiodes is investigated. Hall effect and optoelectronic transport measurements carried out under illumination of 905 nm wavelength light showed that zero-bias SBH in such photodiodes can be effectively tuned in a range between 0.7 and 0.9 eV consistent with the variation in their open-circuit voltage. Shockley-Read-Hall model, which considers the charge recombination through mid-gap and interface states at the p-Gr/n-Si heterojunction, is used to explain the experimentally observed nonlinear dependence of SBH on the incident light. Light induced tunability of SBH at the graphene/semiconductor heterojunction is of great importance especially for the development of new generation optically driven devices in which graphene acts as a functioning element. © 2022 Elsevier B.V., BAP-089, The authors thank the researchers in Center for Materials Research of ?zmir Institute of Technology (?YTE MAM) and Sparks Electronics Ltd. in Turkey for their support in device fabrication processes. This work was supported within the scope of the scientific research project which was accepted by the Project Evaluation Commission of Yasar University under the project number BAP-089. The details for the transfer of monolayer CVD graphene on to Si substrates can be reached via the link https://doi.org/10.1021/nn201207c, The authors thank the researchers in Center for Materials Research of İzmir Institute of Technology (İYTE MAM) and Sparks Electronics Ltd. in Turkey for their support in device fabrication processes. This work was supported within the scope of the scientific research project which was accepted by the Project Evaluation Commission of Yasar University under the project number BAP-089.

International audience; The performance of thermally deposited Sb2Se3 solar cells are severely limited by various bulk and interfacial recombination, instigating a large open-circuit voltage (V-OC) deficit. Ternary Sb-2(S,Se)(3) is considered as a remedy, however, it is also subjected to a dilemma that improvement in V-OC will be escorted by J(SC) loss due to the shrinkage of light harvest. Thus, a gradient of S/Se across the film is a prerequisite to avoid this detrimental compromise. Herein, the incorporation of S in the Sb2Se3 absorber layer evaporated from a CdS buffer layer during vapor transport deposition (VTD) process, and its further self-activated diffusion at the interface upon ambient storage is explored. For the gradient indium tin oxide (ITO)/CdS/Sb-2(S,Se)(3)/Sb2Se3/Au solar cell, the large bandgap Sb-2(S,Se)(3) at the heterojunction side contributes to high V-OC, while the narrow bandgap Sb2Se3 at the top side confirms high J(SC). Sulfur diffusion at the CdS/Sb2Se3 interface also improves the junction quality with an enlarged V-bi, reduced interfacial defects and recombination loss, thus improving V(OC )from 393 to 430 mV. Such V-OC represents the highest value for that of thermally deposited Sb2Se3 solar cells. The champion device also delivers an interesting efficiency of 7.49%. This research provides substantial guidance in exploring efficient approaches to improve the performance of Sb2Se3 solar cells.

Herein, the open-circuit voltage (V[OC]) loss in both polymer solar cells and perovskite solar cells is quantitatively analyzed by measuring the temperature dependence of V[OC] in order to discuss the difference in the primary loss mechanism of V[OC] between them. As a result, the photon energy loss for polymer solar cells is in the range of 0.7–1.4 eV, which is ascribed to temperature-independent and -dependent loss mechanisms while that for perovskite solar cells is as small as about 0.5 eV, which is ascribed to a temperature-dependent loss mechanism. This difference is attributed to the different charge generation and recombination mechanisms between the two devices. The potential strategies for the improvement of V[OC] in both solar cells are further discussed on the basis of the experimental data.

The theoretical mechanism of open-circuit voltages (VOC) in OSCs based on various small molecule organic materials is studied. The structure under investigation is simple planar heterojunction (PHJ) by thermal vacuum evaporation deposition. The various wide band gaps of small molecule organic materials are used to enhance the power conversion efficiency (PCE). The donor materials used in the device include: Alpha-sexithiophene (α-6T), Copper(II) phthalocyanine (CuPc), boron subnaphthalocyanine chloride (SubNc) and boron Subphthalocyanine chloride (SubPc). It is combined with fullerene or SubPc acceptor material to obtain a comprehensive understanding of the charge transport behavior. It is found that the VOC of the device is largely limited by charge transport. This was associated with the space charge effects and hole accumulation. These results are attributed to the improvement of surface roughness and work function after molybdenum trioxide (MoO3) is inserted as an anode buffer layer.