Tailoring the Band Gap in Codoped GaN Nanosheet From First Principle Calculations

Frontiers in Materials

Changjiao Ke¹  Chunling Tian¹  Yundan Gan² 

[1] School of Physical Science and Technology, Southwest University, Chongqing, China;Xi'an Modern Chemistry Research Institute, Xi'an, China;

关键词: photocatalysis;    hybrid density functional;    doped;    band structural calculation;    GaN nanosheet;   

DOI  :  10.3389/fmats.2020.00124

来源: DOAJ

【 摘 要 】

To develop an efficient photocatalyst with intense visible light absorption and high charge mobility is important but still remains a problem. In this work, we have explored the electronic properties of C-monodoped, C-Ge, and C-Sn codoped GaN nanosheets by the hybrid density functional theory in order to find the excellent photocatalytic materials. Results indicate the monodoping of C introduces unoccupied impurity states inside the band gap that serve on recombination centers. Thus, the C monodoping is not suitable to ameliorate visible light absorption. Moreover, the C-Ge and C-Sn codoping not only successfully reduce the band gap of nanosheet GaN but also avoid the unoccupied impurity states. The charge-compensated C-Ge and C-Sn codoped GaN nanosheets are energetically favorable for hydrogen evolution but not insufficient to produce oxygen, indicating that they could serve as Z-scheme photocatalysts. In particular, the minimum defect formation energy of C-Ge is negative and lowest. The C-Ge codoped GaN system has dynamic stability. So, the C-Ge codoped nanosheet GaN is one of the most prospective candidates for the decomposition of hydrogen from water.

【 授权许可】

Unknown