A Solar‐Blind UV Detector Based on Graphene‐Microcrystalline Diamond Heterojunctions

• Published in: Small (Weinheim an der Bergstrasse, Germany) Vol. 13; no. 34
• Main Authors: Wei, Minsong, Yao, Kaiyuan, Liu, Yumeng, Yang, Chen, Zang, Xining, Lin, Liwei
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 01.09.2017
• Subjects: Computer architecture; CVD diamond; Diamond films; Graphene; graphene‐diamond heterojunctions; Heterojunctions; Nanotechnology; Optoelectronic devices; Photodiodes; Silicon substrates; solar‐blind UV detectors; thin film transfer process; Ultraviolet detectors; thin film transfer process; CVD diamond; solar-blind UV detectors; graphene-diamond heterojunctions
• ISSN: 1613-6810; 1613-6829
• DOI: 10.1002/smll.201701328

An ultraviolet detector is demonstrated through a whole‐wafer, thin diamond film transfer process to realize the heterojunction between graphene and microcrystalline diamond (MCD). Conventional direct transfer processes fail to deposit graphene onto the top surface of the MCD film. However, it is found that the 2 µm thick MCD diamond film can be easily peeled off from the growth silicon substrate to expose its smooth backside for the graphene transfer process for high‐quality graphene/MCD heterojunctions. A vertical graphene/MCD/metal structure is constructed as the photodiode device using graphene as the transparent top electrode for solar‐blind ultraviolet sensing with high responsivity and gain factor. As such, this material system and device architecture could serve as the platform for next‐generation optoelectronic systems. A solar‐blind ultraviolet (UV) detector is accomplished through a whole‐wafer, thin diamond film transfer process. By utilizing the smooth backside of the microcrystalline diamond (MCD) film, the UV detector based on high‐quality graphene/MCD heterojunctions is realized for the first time. Based on the graphene/MCD/metal structure, a photodiode device is achieved for solar‐blind ultraviolet sensing with high responsivity and gain factor.