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Defect Engineering for Modulating the Trap States in 2D Photoconductors
Author(s) -
Jiang Jie,
Ling Chongyi,
Xu Tao,
Wang Wenhui,
Niu Xianghong,
Zafar Amina,
Yan Zhenzhong,
Wang Xiaomu,
You Yumeng,
Sun Litao,
Lu Junpeng,
Wang Jinlan,
Ni Zhenhua
Publication year - 2018
Publication title -
advanced materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 10.707
H-Index - 527
eISSN - 1521-4095
pISSN - 0935-9648
DOI - 10.1002/adma.201804332
Subject(s) - trap (plumbing) , materials science , optoelectronics , responsivity , photodetector , dark current , semiconductor , charge carrier , response time , molecule , physics , computer science , computer graphics (images) , quantum mechanics , meteorology
Defect‐induced trap states are essential in determining the performance of semiconductor photodetectors. The de‐trap time of carriers from a deep trap can be prolonged by several orders of magnitude as compared to shallow traps, resulting in additional decay/response time of the device. Here, it is demonstrated that the trap states in 2D ReS 2 can be efficiently modulated by defect engineering through molecule decoration. The deep traps that greatly prolong the response time can be mostly filled by protoporphyrin molecules. At the same time, carrier recombination and shallow traps in‐turn play dominant roles in determining the decay time of the device, which can be several orders of magnitude faster than the as‐prepared device. Moreover, the specific detectivity of the device is enhanced (as high as ≈1.89 × 10 13 Jones) due to the significant reduction of the dark current through charge transfer between ReS 2 and molecules. Defect engineering of trap states therefore provides a solution to achieve photodetectors with both high responsivity and fast response.