Ternary Cd xZn 1− xSe deposited on Ag (1 1 1) by ECALE: Electrochemical and EXAFS characterization

Abstract

This paper reports the characterization of ternary II–VI semiconductor nanocrystals, deposited by the electrochemical atomic layer epitaxy (ECALE) technique. In particular, morphological and structural properties of the ternary compounds of formula Cd x Zn 1− x Se deposited on Ag (1 1 1) have been characterized as a function of composition. The number of the attainable x values is limited by the necessity of using well-defined ZnSe/CdSe deposition sequences. However, the quantitative analysis carried out on the basis of both electrochemical and extended X-ray absorption fine structure (EXAFS) experiments indicates that the ECALE method is a successful way of controlling the composition of Cd x Zn 1− x Se. In addition, the electrochemical measurements show that the amount of deposition is minimum in correspondence to the compound with x = 0.5, thus corroborating the hypothesis of a higher degree of disorder suggested both by morphological and structural investigation. The morphology was studied by atomic force microscopy (AFM). The structure of the films is estimated by EXAFS which is a powerful technique for the analysis of the local structure around chosen atoms.