Promising transport properties of multifunctional monolayer GeSe nanodevices

Abstract

In this study, we conducted a thorough investigation of the transport characteristics of thermoelectric devices, p–n junction diodes, and p–i–n homojunction phototransistors based on monolayer (ML) GeSe. We utilized density functional theory coupled with nonequilibrium Green's functions. The findings revealed that ML GeSe-based nanodevices demonstrate exceptional thermoelectric figures of merit, high rectification ratios, and unique optoelectronic properties including broad-spectrum photoresponse characteristics, high responsivity, and high external quantum efficiency. Considerably, the ML GeSe-based devices exhibit marked anisotropy in their thermoelectric, electronic, and optoelectronic transport properties. They perform better in the zigzag direction than in the armchair direction. Our findings shed light on the multifunctionality and the underlying physical mechanisms of ML GeSe, which is helpful for investigating the application potential of high-performance nanoelectronic devices based on two-dimensional GeSe.