Effect of p-block metal doping on the optical properties of blue-phosphorene phase monolayer GeSe

Expanding the optical absorption of blue-phosphorene phase GeSe and designing it as infrared light driven photocatalysts and photodetectors is of particular significance. In this work, the mechanism of p-block metals (Al, Ga, In, An, Pb, Sb and Bi) doping enhancing the optical performance of monolayer blue-phosphorene phase GeSe was investigated. The effect of all p-block metal doping on the lattice constant of GeSe is very weak. Pb doped system has the smallest formation energy (−4.82 eV). Except for Sn and Pb, other p-block metal doping can introduce deep impurity levels into the band gap of monolayer GeSe, and they can significantly absorb infrared light, especially Ga doped systems. This is due to the emergence of impurity levels that assist the photon transition. The results of this work provide guidance for promoting the application of blue-phosphorene phase GeSe in the field of photocatalysts and photodetectors.