On the electronic properties and performance of new nano thick solar material based on GeSe/SnS hetro-bilayer

Abstract

Motivated by recent works dealing with electronic properties and high carrier mobility of monolayer materials and their potential applications in nano thick solar cells, we investigate the electronic properties and performance of new nano thick solar material based on GeSe/SnS hetro-bilayer. The calculations are performed using DFT calculations within GGA + vdW and HSE06 hybrid functional approximations. Our results indicate that this hetro-bilayer has a direct band gap of 1.48 $$ eV $$ , which is in the optimal range of the efficient single-junction solar cell, and forms the type-II band alignment in which $$ SnS $$ is the donor and $$ GeSe $$ is the acceptor. The values of $$ V_{oc } $$ , $$ FF $$ and $$ J_{sc} $$ using an external quantum efficiency with a limit of 100% are also calculated. Using Scharber model, the upper limit of power conversion efficiency, PCE, is estimated to be 18.74% which is higher than the reported efficiencies of hetro-bilayers. Another estimate of PCE via the descriptor model is found to be 28.83%. These findings make this hetero-bilayer a good candidate for solar energy conversion as an efficient nano-thick solar cell material, and optoelectronics applications as well.