Optical photoresponse of CuS–n-Si radial heterojunction with Si nanocone arrays fabricated by chemical etching

Abstract

The paper deals with the fabrication of a p-CuS-n-Si nanocone heterojunction based highly sensitive broad band photodetector. Cone-like one dimensional Si nanostructures formed by metal assisted chemical etching, with superior antireflection characteristics have been used as templates for fabrication of the heterojunction. Covellite CuS material was synthesized by a simple chemical reaction for used as target material for the fabrication of p-CuS-n-Si nanocone heterojunctions via pulsed laser ablation. The effect of surface texturing of Si (cone like nanostructure vs. planar) on spectral photoresponse and detection is reported.

Photosensitive activity of fabricated core-shell composite nanostructured p-CuO@CuS/n-Si diode for photodetection applications

“…The optimum signal detecting nature of detector is interrupted by noise produced in photodiode which is due to the thermal motion of charge carriers and electron hole pair recombination [ 63 , 64 ]. The detectivity is relatively low for the p-CuS/n-Si diode due to the large dark current and generation of weak photocurrent.…”

Self‐Powered Nanoscale Photodetectors

“…Enlightened by the above works, a large variety of core–shell nanowire heterojunctions have been fabricated. Since the fabrication of ZnO and Si nanowires is facile and reproducible, various semiconductors have been combined with them to form core–shell heterojunctions, such as carbon quantum dots/Si, ZnO/CuS, and ZnO/NiO . Because of the efficient separation of photoexcited holes and electrons in the depletion layer, driven by a built‐in field for the radial heterojunctions, impressive photodetection performances have been achieved for these materials.…”

Solution-Processed Black-Si/Cu2ZnSnS4 Nanocrystal Heterojunctions for Self-Powered Broadband Photodetectors and Photovoltaic Devices

“…Apparently, the observed excellent spectral response without any exterior power supply confirms that the built-in electric field efficiently separates the photogenerated carriers in the space charge region. An additional key parameter of a photodetector is the spectral detectivity ( D ), which indicates its capability to sense very weak optical signals and is defined as where q , J d , and R λ are the electronic charge, dark current density, and spectral responsivity, respectively. Based on eq , the spectral detectivity of the fabricated B–Si/CZTS NC heterojunction at zero bias is plotted in Figure f.…”

“…Significant progress in fabricating a B–Si based heterojunction with band/lattice-matched complementary semiconductors has been made to improve the characteristics of Si-based photodetector and photovoltaic devices. − To date, a number of inorganic/organic materials such as CdS, , CuS, cupric oxide (CuO), molybdenum oxide (MoO 3–x ), reduced graphene oxide, perovskite (Cs-doped FAPbI 3 ), and so forth have been reported to produce B–Si based, complementary metal oxide semiconductor-compatible p–n junction devices to demonstrate their remarkable photovoltaic and photodetection characteristics. Unfortunately, these devices suffer from inferior performance due to a wide bandgap of metal oxides, the presence of a large number of trap defects in chemically grown sulfides, and the relatively poor stability of perovskites.…”