Energy Band Engineering by Remote Doping of Self-Assembled Monolayer Leads to High-Performance IGZO/p-Si Heterostructure Photodetectors.

Metal oxide semiconductors are of great interest for enabling advanced photodetectors. However, operational instability and absence of an appropriate doping technique hinder practical development and commercialization. Here we propose a strategy to dramatically increase the conventional photodetection performance having superior stability in operational and environmental atmospheres. By performing energy band engineering through an octadecylphosphonic acid (ODPA) self-assembled monolayer based doping treatment, the proposed indium-gallium-zinc oxide (IGZO)/p-Si hetero-interfaced devices exhibit greatly enhanced photoresponsive characteristics, including a photo-switching current ratio with a hundredfold increase, and photoresponsivity and detectivity with a 15-fold increase each. The observed ODPA doping effects were investigated through comprehensive analysis with X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), and with a Kelvin probe force microscope (KPFM). Furthermore, the proposed photodetectors fabricated at a four-inch wafer-scale, and demonstrate its excellent operation robustness with consistent performance over 237 days and 20,000 testing cycles. This article is protected by copyright. All rights reserved.