High-Temperature Forward and Reverse Current Transport Mechanisms of AlGaN-Based Solar-Blind UV Photodetector
Yan Gu, Qigao Fan, Yushen Liu, Xifeng Yang, Xuecheng Jiang, Jiarui Guo, Xiu‐Mei Zhang, Naiyan Lu, Guoqing Chen, Guofeng Yang
Abstract
This article describes the fabrication and comprehensive characterization of the metal-organic chemical vapor deposition (MOCVD)-grown back-illuminated Al0.42Ga0.580.58-based p-i-n solar-blind ultraviolet (UV) photodetector (PD). The results reveal that the manufactured device exhibits a cutoff wavelength of approximately 285 nm, which is in agreement with the bandgap of Al0.42Ga0.580.58. In addition, a solar-blind/visible light rejection ratio of over <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$10^{{4}}$ </tex-math></inline-formula> and a photocurrent/dark current ratio of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$10^{{4}}$ </tex-math></inline-formula> can be obtained for the p-i-n UV PD. Moreover, the current–voltage–temperature ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${I} - {V} - {T}$ </tex-math></inline-formula> ) measurements were performed to explore the forward and reverse current transport mechanisms for the high-temperature reliability analysis of the device. The tunneling current was found to make the dominant contribution to the forward current. Furthermore, carrier-hopping conduction and Poole–Frenkel emission models convincingly explained the observed reverse temperature-dependent dark <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${I} - {V}$ </tex-math></inline-formula> characteristics.