Self-Powered, High-Speed and Visible鈥揘ear Infrared Response of MoO3鈥搙/n-Si Heterojunction Photodetector with Enhanced Performance by Interfacial Engineering

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• 作者：Chuanxi Zhao ; Zhimin Liang ; Mingze Su ; Pengyi Liu ; Wenjie Mai ; Weiguang Xie
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2015
• 出版时间：November 25, 2015
• 年：2015
• 卷：7
• 期：46
• 页码：25981-25990
• 全文大小：641K
• ISSN：1944-8252

文摘

Photodetectors with a wide spectrum response are important components for sensing, imaging, and other optoelectronic applications. A molybdenum oxide (MoO_3鈥?i>x)/Si heterojunction has been applied as solar cells with great success, but its potential in photodetectors has not been explored yet. Herein, a self-powered, high-speed heterojunction photodetector fabricated by coating an n-type Si hierarchical structure with an ultrathin hole-selective layer of molybdenum oxide (MoO_3鈥?i>x) is first investigated. Excellent and stable photoresponse performance is obtained by using a methyl group passivated interface. The heterojunction photodetector demonstrated high sensitivity to a wide spectrum from 300 to 1100 nm. The self-powered photodetector shows a high detectivity of (鈭?.29 脳 10¹² cmHz^1/2 W^鈥?) and fast response time (1.0 渭s). The excellent photodetecting performance is attributed to the enhanced interfacial barrier height and three-dimensional geometry of Si nanostructures, which is beneficial for efficient photocarrier collection and transportation. Finally, our devices show excellent long-term stability in air for 6 months with negligible performance degradation. The thermal evaporation method for large-scale fabrication of MoO_3鈥?i>x/n-Si photodetectors makes it suitable for self-powered, multispectral, and high-speed response photodetecting applications.