First-principle studies of the optoelectronic properties of ASnF3 (A = Na, K, Rb and Cs)

In this paper, we communicate a new type of Auger-free luminescence (AFL) compounds, alkali tin fluorides ASnF(3) (A = Na, K, Rb and Cs). The luminescence in these compounds-6 F, originates due to the electron transition from the top valence band (VB) of tin -s orbital to the outermost core levels of halogen, i.e., halogen-p orbital (s-p transitions). The AFL of these compounds is expected to be of L-type. Furthermore, the electronic band structures and optical properties such as dielectric functions, refractive index and energy loss function are also investigated using ab initio calculations.