Direct laser writing of vertical junctions in graphene oxide films for broad spectral position-sensitive detectors

Nanophotonics

article

Rui Feng¹  Ran Liu¹  Laigui Hu¹  Youwei Zhang¹  Muhammad Zaheer¹  Zhi-Jun Qiu¹  Chunxiao Cong¹  Qingmiao Nie²  Yajie Qin¹ 

[1] State Key Laboratory of ASIC and System, School of Information Science and Technology, Fudan University;Department of Applied Physics, Zhejiang University of Technology

关键词: graphene;    laser scribing;    photodetectors;    position-sensitive detectors;    reduced graphene oxide;   

DOI  :  10.1515/nanoph-2018-0070

学科分类：社会科学、人文和艺术（综合）

来源: De Gruyter

【 摘 要 】

Heterostructures with built-in electric fields are crucial for charge separation and lateral photovoltaic effect in current position-sensitive detectors (PSDs), which have to be produced by combining semiconductors with metal or other semiconductors to form various vertical junctions (e.g. Schottky junctions) via complicated and high-cost manufacture processes. In the present work, it was found that vertical junctions can be directly written and patterned inside graphene oxide (GO) films with gradient C/O ratios by laser scribing due to the optical filter effect of the films and the formation of reduced GO (rGO) layers. Such junctions were verified to show the capability for high-precision position sensing on the micrometer scale, owing to the lateral photovoltaic effect. These self-powered laser-scribed PSDs can exhibit a small nonlinearity of <5.4%, which is far less than the acceptable level of 15%. A fast response time of about 1 ms can be obtained under a zero bias voltage, which is the fastest speed among the photodetectors based on pure rGO. Electron lateral diffusion in the upper layers of the laser-scribed devices was found to play a main role. These suggest that laser-scribed vertical junctions inside rGO are promising for high-precision displacement sensing, with the capability of low cost, flexibility, and passive operation mode.

【 授权许可】

CC BY