The structural and electronic properties of various defects and doping effects in the monolayer BP have been systematically investigated using density-functional theory (DFT). It is shown that the monolayer BP is a planar compound with a direct bandgap value of 0.87 eV. For the B vacancy, the direct bandgap values are 0.912 eV, whereas the indirect bandgap value is 0.852 eV for the P vacancy. The structure remains a direct bandgap semiconductor, and the bandgap values are 0.53 eV, 0.72 eV, and 0.68 eV, respectively, for B anti-site, P anti-site, and exchange defects. Finally, we have found the direct bandgap values of 0.91 eV, 0.93 eV, and 0.96 eV with Al, Ga, and In dopant atoms into the monolayer BP structure, respectively. These results provide strategies on modifying the properties of monolayer BP, which will be favorable to the novel optoelectronic device applications.

已使用密度泛函理论（DFT）系统地研究了单层BP中各种缺陷的结构和电子性质以及掺杂效应。可以看出，单层BP是平面带状化合物，其直接带隙值为0.87eV。对于B空位，直接带隙值为0.912eV，而对于P空位，间接带隙值为0.852eV。该结构仍然是直接的带隙半导体，对于B反位，P反位和交换缺陷，带隙值分别为0.53 eV，0.72 eV和0.68 eV。最后，我们发现Al，Ga和In掺杂原子分别进入单层BP结构时的直接带隙值为0.91 eV，0.93 eV和0.96 eV。这些结果为改变单层BP的性能提供了策略，