Self-powered and fast photodetector based on graphene/MoSe2/Au heterojunction

• Published in: Superlattices and microstructures Vol. 130; pp. 87 - 92
• Main Authors: Liu, Beiyun, Zhao, Chen, Chen, Xiaoqing, Zhang, Linrui, Li, Yufo, Yan, Hui, Zhang, Yongzhe
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.06.2019
• Subjects: 2D materials; Photodetector; Self-powered; Photodetector; 2D materials; Self-powered
• ISSN: 0749-6036; 1096-3677
• DOI: 10.1016/j.spmi.2019.04.021

Two-dimensional (2D) materials have been demonstrated to be ideal candidates to design high performance photodetector owing to their novel optoelectronic features. However, large number of such simple photodetectors are photoconductive, which need external voltage to work effectively. In this paper, we proposed a kind of self-powered photodetector composed of semi-metallic graphene, semiconducting MoSe2 and Au to generate two asymmetric contacts because these three materials owns different work functions. On one hand, the open-circuit voltage between MoSe2 and Au enables the device to achieve self-powered photodetection with the high responsivity of 89.5 mA/W and specific detectivity of 2.24 × 1010 jones. On the other hand, because of the ohmic contact between MoSe2 and graphene, electrons can be transferred rapidly from MoSe2 to graphene, leading to a short response time of only 9.6 ms. In addition, this photodetector possesses broader spectrum detection from 450 nm to 900 nm compared with the one made by MoS2 as it owns much narrower bandgap. Our work offers a new approach for optoelectronic device design with low power consumption but high responsivity. •Photodetector based on Graphene/MoSe2/Au was fabricated forming asymmetric contacts.•Self-powered photodetection achieves and the high responsivity is up to 89.5 mA/W.•The electrons can be rapidly transferred and the response time is only 9.6 ms.•This photodetector possesses broad spectrum detection from 450 nm to 900 nm.