Raman characterization of a new Te-rich binary compound: CdTe2.
Structural characterization by Raman spectroscopy of CdTe thin films electrodeposited in acidic conditions is considered in this work. This study focuses on the evolution of material properties as a function of the applied potential and the film thickness, demonstrating the possibility to obtain a new Te-rich compound with a II/VI ratio of 1/2 under specific bath conditions. Raman measurements carried out on etched samples first allow the elimination of the assumption of a mixture of phases CdTe + Te and tend to confirm the formation of the CdTe(2) binary compound. The signature of this phase on the Raman spectrum is the increase of the LO band intensity compared to that obtained for the CdTe. The influence of the laser power is also considered. While no effect is observed on CdTe films, the increase of the incident irradiation power leads to the decomposition of the CdTe(2) compound into two more stable phases namely CdTe and Te.
Rousset
Jean
J
IRDEP Institut de Recherche et Developpement sur l'Energie Photovoltaique, UMR, EDF-CNRS-ENSCP, Chatou, France. jean-externe.rousset@edf.fr
Rzepka
Edouard
E
Lincot
Daniel
D