Excellent Excitonic Photovoltaic Effect in 2D CsPbBr₃/CdS Heterostructures

Abstract

P-n photovoltaic junctions are essential building blocks for optoelectronic devices for energy conversion. However, this photovoltaic efficiency has almost reached its theoretical limit. Here, a brand-new excitonic photovoltaic effect in 2D CsPbBr 3 /CdS heterostructures is revealed. These heterostructures, synthesized by epitaxial growth, display a clean interface and a strong interlayer coupling. The excitonic photovoltaic effect is a function of both the built-in equilibrium electrical potential energy and the chemical potential energy, which is generated by the significant concentration gradient of electrons and holes at the heterojunction interface. Excitingly, this novel photovoltaic effect results in a large open-circuit voltage of 0.76 V and a high power conversion efficiency of 17.5%. In addition, high photodetection performance, including a high photoswitch ratio (I light /I dark) of 10 5 and a fast response rate of 23 µs are obtained. These findings provide a new platform for photovoltaic applications.

All‐Inorganic CsPbBr3 Perovskite Nanocrystals/2D Non‐Layered Cadmium Sulfide Selenide for High‐Performance Photodetectors by Energy Band Alignment Engineering

“…The PL decay curves of the pristine CsPbBr 3 NCs and CsPbBr 3 NCs/2D CdS x Se 1-x can be fitted with a biexponential decay function. [3,22] The obtained average lifetimes for © 2021 Wiley-VCH GmbH pristine CsPbBr 3 NCs and CsPbBr 3 NCs/2D CdS x Se 1-x are 11.26 and 1.38 ns, respectively. It is obvious that the PL lifetime of the CsPbBr 3 NCs/2D CdS x Se 1-x heterostructures is much shorter than that of the pristine CsPbBr 3 NCs.…”

“…In recent years, organic-inorganic hybrid perovskites have been intensively studied in optoelectronic devices as promising optoelectronic materials due to their large light absorption coefficient, high carrier mobility, and long charge carrier diffusion length. [1][2][3] However, the poor ambient stability of organic components in the hybrid perovskites restricts their practical application. [4] To resolve this issue, various dimensional all-inorganic lead halide perovskites (CsPbX 3 , X = Cl, Br, I) have been widely employed as alternative materials, [5] including 0D quantum dots, [6] 1D nanowires, [7] and 2D nanosheets.…”

Recent Advances in 2D Materials for Photodetectors

“…Very recently, by combining 2D organic and inorganic materials, Jin et al. [ 75 ] reported the novel excitonic photovoltaic effect of 2D CsPbBr 3 /CdS flake heterojunction. Figure a shows the schematic diagram of typical vertical photodiode junction under 532 nm illumination in this research.…”

CdS nanobelt-based self-powered flexible photodetectors with high photosensitivity

“…Cadmium sulfide (CdS) is a physiochemically interesting intermediate direct bandgap (2.4 eV) semiconductor with speedy response, low work function, high photosensitivity, large refractive index, and exceptional chemical and thermal stability. Therefore, it is a fascinating and potential candidate for selfpowered photodetectors [13][14][15][16][17][18][19][20][21][22][23] . For instance, Dai et al reported FPSD composed of p-Si/n-CdS nanowires heterostructure, which respond beyond the bandgap limitation with fast response speed at zero bias 24 .…”