Three-dimensional a-Si/a-Ge radial heterojunction near-infrared photovoltaic detector

Abstract In this work, three-dimensional (3D) radial heterojunction photodetectors (PD) were constructed over vertical crystalline Si nanowires (SiNWs), with stacked hydrogenated amorphous germanium (a-Ge:H)/a-Si:H thin film layer as absorbers. The hetero absorber layer is designed to benefit from t...

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Bibliographic Details
Main Authors: Xiaolin Sun, Ting Zhang, Linwei Yu, Ling Xu, Junzhuan Wang
Format: article
Language:EN
Published: Nature Portfolio 2019
Subjects:
R
Q
Online Access:https://doaj.org/article/f9224dce6086479a844eea524917014c
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Summary:Abstract In this work, three-dimensional (3D) radial heterojunction photodetectors (PD) were constructed over vertical crystalline Si nanowires (SiNWs), with stacked hydrogenated amorphous germanium (a-Ge:H)/a-Si:H thin film layer as absorbers. The hetero absorber layer is designed to benefit from the type-II band alignment at the a-Ge/a-Si hetero-interface, which could help to enable an automated photo-carrier separation without exterior power supply. By inserting a carefully controlled a-Si passivation layer between the a-Ge:H layer and the p-type SiNWs, we demonstrate first a convenient fabrication of a new hetero a-Ge/a-Si structure operating as self-powered photodetectors (PD) in the near-infrared (NIR) range up to 900 nm, indicating a potential to serve as low cost, flexible and high performance radial junction sensing units for NIR imaging and PD applications.