An ultrathin MoSe <sub>2</sub> photodetector with near-perfect absorption
Wen Du, Peng Yu, Juntong Zhu, Caihong Li, Hao Xu, Jihua Zou, Cuo Wu, Qiye Wen, Haining Ji, Tianji Liu, Yanbo Li, Guifu Zou, Jiang Wu, Zhiming Wang
Abstract
Abstract An ultrathin near-perfect MoSe 2 absorber working in the visible regime is demonstrated theoretically and experimentally, and it consists of a MoSe 2 /Au bi-layer film. The polymer-assisted deposition method is used to synthesize MoSe 2 films, which can reduce the roughness and thus improve the film absorption. Simulation results show that the absorption of the absorber with 22 nm MoSe 2 reaches to larger than 90% between 628.5 nm and 718 nm with a peak value up to 99.5% at 686 nm. Moreover, the measured absorption also shows near-perfect absorption of this simple absorber. Finally, an ultrathin photodetector is fabricated based on this perfect absorber and shows on/off reproducibility and remarkable photocurrent, which is three orders of magnitude higher than the dark current.