The theoretical Shockley-Queisser limit of photon-electricity conversion in a conventional p-n junction could be potentially overcome by the bulk photovoltaic effect that uniquely occurs in non-centrosymmetric materials. Using strain-gradient engineering, the flexo-photovoltaic effect, that is, the strain-gradient-induced bulk photovoltaic effect, can be activated in centrosymmetric semiconductors, considerably expanding material choices for future sensing and energy applications. Here we report an experimental demonstration of the flexo-photovoltaic effect in an archetypal two-dimensional material, MoS, by using a strain-gradient engineering approach based on the structural inhomogeneity and phase transition of a hybrid system consisting of MoS and VO. The experimental bulk photovoltaic coefficient in MoS is orders of magnitude higher than that in most non-centrosymmetric materials. Our findings unveil the fundamental relation between the flexo-photovoltaic effect and a strain gradient in low-dimensional materials, which could potentially inspire the exploration of new optoelectronic phenomena in strain-gradient-engineered materials.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1038/s41565-021-00919-y | DOI Listing |
Small
January 2025
Department of Materials Science and Engineering, City University of Hong Kong, Kowloon, Hong Kong, 999077, China.
Carbazole-derived self-assembled monolayers (SAMs) are promising materials for hole-extraction layer (HEL) in conventional organic photovoltaics (OPVs). Here, a SAM Cbz-2Ph derived from 3,6-diphenylcarbazole is demonstrated. The large molecular dipole moment of Cbz-2Ph allows the modulation of electrode work function to facilitate hole extraction and maximize photovoltage, thus improving the OPV performance.
View Article and Find Full Text PDFNano Lett
January 2025
Institute of Photoelectronic Thin Film Devices and Technology, State Key Laboratory of Photovoltaic Materials and Cells, Tianjin Key Laboratory of Efficient Solar Energy Utilization, Ministry of Education Engineering Research Center of Thin Film Photoelectronic Technology, Nankai University, 300350 Tianjin, China.
Hematite is a promising material for photoelectrochemical (PEC) water oxidation, but its photocurrent is limited by bulk charge recombination and poor oxidation kinetics. In this study, we report a high-performance FeO photoanode achieved through gradient surface gallium doping, utilizing a GaO overlayer on FeOOH precursors via atomic layer deposition (ALD) and co-annealing for Ga diffusion. The Ga-doped layer passivates surface states and modifies the band structure, creating a built-in electric field that enhances the charge separation efficiency.
View Article and Find Full Text PDFNano Lett
January 2025
Guangdong Provincial Key Laboratory of Optical Information Materials and Technology, Institute of Electronic Paper Displays, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou 510006, P. R. China.
Two-dimensional ferroelectric materials can generate a bulk photovoltaic effect, making them highly promising for self-powered photodetectors. However, their practical application is limited by a weak photoresponse due to a weak transition strength and wide band gap. In this study, we construct a van der Waals heterojunction using NbOI, which has significant in-plane polarization, with a highly absorbing MoSe layer.
View Article and Find Full Text PDFNat Commun
January 2025
National Key Laboratory of Electronic Films and Integrated Devices, School of Integrated Circuit Science and Engineering, University of Electronic Science and Technology of China, Chengdu, P. R. China.
Suppressing deep-level defects at the perovskite bulk and surface is indispensable for reducing the non-radiative recombination losses and improving efficiency and stability of perovskite solar cells (PSCs). In this study, two Lewis bases based on chalcogen-thiophene (n-Bu4S) and selenophene (n-Bu4Se) having tetra-pyridine as bridge are developed to passivate defects in perovskite film. The uncoordinated Pb and iodine vacancy defects can interact with chalcogen-concave group and pyridine group through the formation of the Lewis acid-base adduct, particularly both the defects can be surrounded by concave molecules, resulting in effective suppression charge recombination.
View Article and Find Full Text PDFSmall
January 2025
Department of Physics and Materials Science, University of Luxembourg, Esch-sur-Alzette, L-4365, Luxembourg.
Cu(In, Ga)S demonstrates potential as a top cell material for tandem solar cells. However, achieving high efficiencies has been impeded by open-circuit voltage (V) deficits arising from In-rich and Ga-rich composition segregation in the absorber layer. This study presents a significant improvement in the optoelectronic quality of Cu(In, Ga)S films through the mitigation of composition segregation in three-stage co-evaporated films.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!