DFT coupled with NEGF study of a promising two-dimensional channel material: black phosphorene-type GaTeCl

A stable three-dimensional layered GaTeCl bulk counterpart is first known from experiment since 1980s. In this study, we propose a two-dimensional GaTeCl, the band structure of which has a tendency of intrinsic direct-to-indirect band gap transitions as a result of a decrease in the layer number, while the changes in the band gap value are minor. The GaTeCl monolayer possesses a wide indirect band gap of 3.06 eV and high hole mobility of up to 4710 cm² V^-1 s^-1, which, intriguingly, can be converted into direct band-gap semiconductors under a slight tensile strain. The GaTeCl monolayer is calculated to have an ideal cleavage energy of about 32 meV per atom; therefore, the synthesis of GaTeCl monolayer through exfoliation of bulk GaTeCl is available. In this regard, we simulate a monolayer GaTeCl MOSFETs device based on first-principles method quantum transport approach. The underlying device performance could pave the way for it to be a promising candidate as a suitable FET channel material.