Tunable band structure and effective mass of disordered chalcopyrite

TL;DR

This paper investigates how disorder affects the band structure and effective mass in chalcopyrite semiconductors, which are promising for photovoltaic applications due to their efficiency and material abundance.

Contribution

It provides a detailed analysis of the tunability of band structure and effective mass in disordered chalcopyrite materials, advancing understanding for photovoltaic device optimization.

Findings

Disorder significantly influences the band gap and effective mass.

Tunable electronic properties can be achieved through controlled disorder.

Results suggest potential for optimizing chalcopyrite materials for solar cells.

Abstract

Although new photovoltaic materials, such as organic perovskites, have attracted much attention recently,\cite{perov1,perov2,perov3} zinc-blende semiconductors still play an important role, owing to their high efficiency and stability in real environments. For example, Cu$_2$ZnSnSe$_4$ \cite{AM2013} (CZTS) and Cu(In,Ga)Se$_2$ \cite{JACS2008} (CIGS), which are both based on chalcopyrite CuGa$X_2$ ($X=$ S, Se), have been considered as potential candidates for photovoltaics. It has been reported recently that the efficiency of CIGS has gone beyond 20\%, which is close to that of polycrystalline s ilicon.\cite{efficiency2014} Furthermore, photovoltaic devices related to CZTS have gained attention because they solely contain abundant and nontoxic materials.\cite{AM2013,CZTS}