Impacts of point defects on shallow doping in cubic boron arsenide: A first principles study

Cubic boron arsenide (BAs) stands out as a promising material for advanced electronics, thanks to its exceptional thermal conductivity and ambipolar mobility. However, effective control of p- and n-type doping in BAs poses a significant challenge, mostly as a result of the influence of defects. In the present study, we employed density functional theory (DFT) to explore the impacts of the common point defects and impurities on p-type doping of Be${}_{\text{B}}$ and Si${}_{\text{As}}$, and on n-type doping of Si${}_{\text{B}}$ and Se${}_{\text{As}}$. We found that the most favorable point defects formed by C, O, and Si are C${}_{\text{As}}$, O${}_{\text{B}}$O${}_{\text{As}}$, Si${}_{\text{As}}$, C${}_{\text{As}}$Si${}_{\text{B}}$, and O${}_{\text{B}}$Si${}_{\text{As}}$, which have formation energies of less than $1.5\mathrm{eV}$. While the O impurity detrimentally affects both p- and n-type dopings, C and Si impurities are harmful for n-type dopings, making n-type doping a potential challenge. Interestingly, the antisite defect pair As${}_{\text{B}}$B${}_{\text{As}}$ benefits both p- and n-type doping. The doping limitation analysis presented in this study can potentially pave the way for strategic development in the area of BAs-based electronics.