Abstract
Quaternary chalcogenides of different structure types continue to be of interest due to the novel physical
properties they exhibit and for applications ranging from optoelectronics to energy-related technologies. Herein
we report on the electronic and thermal properties of spinel CuInSnS4. UV–vis–NIR spectroscopy indicates strong
absorption in the visible-light region with an indirect bandgap of 1.52 eV. First-principles computations
corroborate our experimental data and reveal that the band-edge electronic properties are due to strong p ô€€€ d and
s ô€€€ p hybridization and antibonding interactions. Analyses of temperature-dependent thermal properties together
with first principles simulations reveal strong anharmonicity and low-lying optical branches that hybridize with
the acoustic modes effectively suppressing thermal conductivity. This intrinsically very low thermal conductivity
is much lower than that of related chalcogenides. Our findings are discussed in the light of ongoing interest in
quaternary metal chalcogenide materials and may aid in the development of this and similar chalcogenides for
applications of interest.
