Highly Sensitive Ultraviolet Photodetector Based on an AlGaN/GaN HEMT with Graphene‐On‐p‐GaN Mesa Structure

Autor: Bhishma Pandit, Hyeon‐Sik Jang, Yunjo Jeong, Sangmin An, S. Chandramohan, Kyung Kyu Min, Sang Min Won, Chel‐Jong Choi, Jaehee Cho, Seongin Hong, Keun Heo
Jazyk: angličtina
Rok vydání: 2023
Předmět:
Zdroj: Advanced Materials Interfaces, Vol 10, Iss 12, Pp n/a-n/a (2023)
Druh dokumentu: article
ISSN: 2196-7350
DOI: 10.1002/admi.202202379
Popis: Abstract The advantageous role of 2D electron gas presence at the AlGaN/GaN interface attracts huge interest in the field of GaN‐based ultraviolet photodetector technology. However, the presence of high dark current deteriorates the photodetector performance by diminishing several figures of merit. In this work, enhanced figures of merit are demonstrated by employing interdigitated p‐GaN finger structure on the top of the AlGaN/GaN heterostructure. The commonly present high dark current in p‐GaN/AlGaN/GaN planar photodetector is largely reduced (from ≈µA to few pA) by etching the p‐GaN, excluding the electrode region. Furthermore, by using a graphene transparent electrode along with the p‐GaN interdigitated fingers on AlGaN/GaN heterostructure, ultraviolet photodetectors with superior sensitivity (3.55 × 106) and ultrahigh detectivity (1.91 × 1014 cm Hz1/2 W−1) are realized at 360 nm. A comparison of graphene/p‐GaN and Ni/Au/p‐GaN interdigitated fingers and planar p‐GaN (with interdigitated graphene contacts) all on AlGaN/GaN heterostructure allows to understand the dominant roles of electrode transparency and the heterojunction structure. The simple and high electron mobility transistor‐compatible fabrication process of UV detectors provides a unique application in the field of UV sensing technology.
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