Performance Enhancement of Graphene Photodetectors via In Situ Preparation of TiO2 on Graphene Channels

Graphene has been considered a promising material for high‐performance photodetectors due to its broad light‐absorption bandwidth and fast photoresponse time. However, weak light absorption (2.3%) in monolayer graphene results in the relatively low photoresponsivity of graphene photodetectors (GPDs)...

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Bibliographic Details
Published in:Advanced materials technologies 2019-03, Vol.4 (3), p.n/a
Main Authors: Cheng, Chuantong, Yang, Hongru, Huang, Beiju, Zhang, Huan, Fan, Hui, Zhang, Xingfei, Mao, Xurui, Gui, Qiang, Yang, Xiaowei, Pei, Weihua, Chen, Hongda
Format: Article
Language:English
Subjects:
broadband
graphene photodetectors
high stability
titanium dioxide
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Summary:Graphene has been considered a promising material for high‐performance photodetectors due to its broad light‐absorption bandwidth and fast photoresponse time. However, weak light absorption (2.3%) in monolayer graphene results in the relatively low photoresponsivity of graphene photodetectors (GPDs). Moreover, the operation stability of GPDs has become another commercialization bottleneck due to the environmental sensitivity of graphene materials. Hence, developing a compact GPD with high photoresponsivity and high stability is critical and significant. Here, an in situ, thermally oxidized TiO2 layer is used to enhance both the photoresponsivity and stability of a metal–graphene–metal photodetector. Moreover, the fabricated GPDs operate well under zero bias, avoiding the large dark current produced in traditional GPDs. These results address key challenges for high‐performance photodetectors and are promising for the development of complementary metal–oxide–semiconductor compatible graphene‐based optoelectronic applications, such as monolithic optoelectronic‐integrated broadband image sensor chips. A high performance graphene photodetectors (GPD) assisted by a thermally oxidized TiO2 layer is designed and fabricated. This photodetector operates stably under incident light at wavelengths from 365 to 1600 nm, covering the ultraviolet, visible, and infrared spectral ranges. At 1600 nm, the proportion of photocurrent reaches about 33%, which is the best result obtained from the reported photoconductive GPDs.
ISSN:2365-709X
2365-709X
DOI:10.1002/admt.201800548