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 originates due to the electron transition from the top valence band (VB) of tin-[Formula: see text] orbital to the outermost core levels of halogen, i.e., halogen-[Formula: see text] orbital ([Formula: see text]-[Formula: see text] 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.