Quick Optical Identification of the Defect Formation in Monolayer WSe2 for Growth Optimization

Nanoscale Research Letters

Haitao Chen¹  Jun He²  Shaohua Tao²  Lin Li²  Han Huang²  Xiaoming Yuan²  Long Fang²  Junnan Ding²  Gen Chen³ 

[1] College of Advanced Interdisciplinary Studies, National University of Defense Technology;Hunan Key Laboratory of Super Micro-structure and Ultrafast Process, School of Physics and Electronics, Central South University;School of Materials Science and Engineering, Central South University;

关键词: WSe2;    Defects;    Crystal stability;    Photoluminescence;    Raman scattering;   

DOI  :  10.1186/s11671-019-3110-z

来源: DOAJ

【 摘 要 】

Abstract Bottom-up epitaxy has been widely applied for transition metal dichalcogenides (TMDCs) growth. However, this method usually leads to a high density of defects in the crystal, which limits its optoelectronic performance. Here, we show the effect of growth temperature on the defect formation, optical performance, and crystal stability in monolayer WSe2 via a combination of Raman and photoluminescence (PL) spectroscopy study. We found that the defect formation and distribution in monolayer WSe2 are closely related to the growth temperature. These defect density and distribution can be controlled by adjusting the growth temperature. Aging experiments directly demonstrate that these defects are an active center for the decomposition process. Instead, monolayer WSe2 grown under optimal conditions shows a strong and uniform emission dominated by neutral exciton at room temperature. The results provide an effective approach to optimize TMDCs growth.

【 授权许可】

Unknown