Huang Hongfu, Peng Junhao, Li Zixuan, Dong Huafeng, Huang Le, Wen Minru, Wu Fugen
School of Physics and Optoelectronic Engineering, Guangdong University of Technology, Guangzhou510006, China.
Guangdong Provincial Key Laboratory of Information Photonics Technology, Guangdong University of Technology, Guangzhou510006, China.
J Phys Chem Lett. 2022 Dec 1;13(47):10988-10993. doi: 10.1021/acs.jpclett.2c03306. Epub 2022 Nov 20.
Defects are inevitable in two-dimensional materials due to the growth condition, which results in many unexpected changes in materials' properties. Here, we have mainly discussed the nonradiative recombination dynamics of PtSe monolayer without/with native point defects. Based on first-principles calculations, a shallow p-type defect state is introduced by a Se antisite, and three n-type defect states with a double-degenerate shallow defect state and a deep defect state are introduced by a Se vacancy. Significantly, these defect states couple strongly to the pristine valence band maximum and lead to the enhancement of the in-plane vibrational E mode. Both factors appreciably increase the nonadiabatic coupling, accelerating the electron-hole recombination process. An explanation of PtSe-based photodetectors with the slow response, compared to conventional devices, is provided by studying this nonradiative transitions process.
