Highly sensitive phototransistors based on two-dimensional GaTe nanosheets with direct bandgap
photodetector, gallium telluride, two-dimensional, semiconductor, nanosheet
Highly sensitive phototransistors based on two-dimensional (2D) GaTe nanosheet have been demonstrated. The performance (photoresponsivity, detectivity) of the GaTe nanosheet phototransistor can be efficiently adjusted by using the applied gate voltage. The devices exhibit an ultrahigh photoresponsivity of 274.3 AW–1. The detectivity of 2D GaTe devices is ~1012 Jones, which surpasses that of currently-exploited InGaAs photodetectors (1011–1012 Jones). To reveal the origin of the enhanced photocurrent in GaTe nanosheets, theoretical modeling of the electronic structures was performed to show that GaTe nanosheets also have a direct bandgap structure, which contributes to the promotion of photon absorption and generation of excitons. This work shows that GaTe nanosheets are promising materials for high performance photodetectors.
Tsinghua University Press
Pingan Hu,Jia Zhang,Mina Yoon,Xiao-Fen Qiao,Xin Zhang,Wei Feng,Pingheng Tan,Wei Zheng,Jingjing Liu,Xiaona Wang,Juan C. Idrobo,David B. Geohegan,Kai Xiao, Highly sensitive phototransistors based on two-dimensional GaTe nanosheets with direct bandgap. NanoRes.2014, 7(5): 694–703