High carrier mobility and polarization sensitivity of AlN/Hf2CO2 heterojunction photodetector

This paper utilizes density functional theory to investigate the structural stability, electronic, optical properties, and photogalvanic effect of the AlN/Hf2CO2 heterojunction. The high stability of the AlN/Hf2CO2 heterojunction is confirmed by calculating the formation energy and performing ab initio molecular dynamics simulations. Demonstrating a type II heterojunction, characterized by an indirect band-gap semiconductor, the heterostructure exhibits a bandgap of 1.518 eV. In the zigzag and armchair directions, the hole mobility of the AlN/Hf2CO2 heterojunction stands at 16835 cm2/Vs and 4209 cm2/Vs, indicating strong electrical conductivity. Compared to monolayer materials, the AlN/Hf2CO2 heterojunction exhibits enhanced light absorption in the ultraviolet and visible light ranges, with a peak absorption at 223 nm reaching a value of 7.62 x 10-5 cm-1. In the zigzag direction, a sensitivity of 27 can be attained by the photogalvanic effect. There is a certain degree of application value in the field of photodetectors.