Raman spectrum of Cu2CdSnSe4 stannite structure semiconductor compound

Abstract

Raman spectrum of Cu2CdSnSe4 quaternary semiconductor compounds with tetragonal stannite-type structure (space group I4¯2m), a material which has been recognized recently as a potential candidate for thermoelectric applications, has been studied. Most of the fourteen Raman lines expected for this compound according to group theory analysis were observed in the spectrum. Besides to the two strongest A1-symmetry stannite modes at 172 and 192 cm−1 originated from the motion of Se anion around the Cu and Sn cations which remain at rest, the leftover observed Raman lines were tentatively assigned to specific eigenmodes of the stannite crystal structure by comparing these line frequencies with those obtained for this compound from IR measurements as well as with those calculated Raman modes for the Cu2ZnSnSe4 stannite-compound reported in the literature. Two spurious Raman lines related to the presence in this compound of SnSe and SnSe2 minority secondary phases have also been found in the Raman spectrum.