Fast Response GaAs Photodetector Based on Constructing Electron Transmission Channel

Shuai Guo,Jilong Tang,Dan Fang,Lei Liao,Xue Chen,Dengkui Wang,Xuan Fang,Zhipeng Wei

doi:10.3390/cryst11101160

Shuai Guo, Jilong Tang + Show 6 more

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https://doi.org/10.3390/cryst11101160

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Abstract

Low-dimensional GaAs photodetectors have drawn a great deal of attention because of their unique absorption properties and superior responsivity. However, their slow response speed caused by surface states presents challenges. In this paper, a mixed-dimensional GaAs photodetector is fabricated utilizing a single GaAs nanowire (NW) and a GaAs 2D non-layer sheet (2DNLS). The photodetector exhibits a fast response with a rise time of ~4.7 ms and decay time of ~6.1 ms. The high-speed performance is attributed to an electron transmission channel at the interface between the GaAs NW and GaAs 2DNLS. Furthermore, the fast electron channel is confirmed by eliminating interface states via wet passivation. This work puts forward an effective way to realize a high-speed photodetector by utilizing the surface states of low-dimensional materials.

Highlights

State Key Laboratory for Chemo/Biosensing and Chemometrics, School of Physics and Electronics, Abstract: Low-dimensional GaAs photodetectors have drawn a great deal of attention because of their unique absorption properties and superior responsivity
As is well-known, low-dimensional materials have a large number of surface states caused by dangling bonds, which seriously hinder the performance of optoelectronic devices [11,12]
For NW photodetectors, photo-generated electrons are usually trapped by the surface states, which leads to low responsivity

Summary

Introduction

State Key Laboratory for Chemo/Biosensing and Chemometrics, School of Physics and Electronics, Abstract: Low-dimensional GaAs photodetectors have drawn a great deal of attention because of their unique absorption properties and superior responsivity. Their slow response speed caused by surface states presents challenges. In order to improve the properties of photodetectors, many efforts have been carried out to eliminate the surface states [13,14,15,16] These include applying sulfur passivation to remove surface states through saturating dangling bonds in GaAs NWs, which effectively reduces the dark current of the corresponding device. The fast response is realized through forming a high-speed minority transmission channel by utilizing surface states in a GaAs NW/GaAs 2DNLS photodetector

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