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Chemical and microstructural study in radio frequency sputtered CdTe oxide films prepared at different N2O pressures. Oxygen incorporation and film resputtering

“…The study of the optical properties of a-CdTe:O films revealed that the optical energy gap can be tuned between 1.48 eV and 3.35 eV by controlling the oxygen content in the films [1]. Preparation of CdTe oxide films is usually carried out by radio frequency (rf) sputtering deposition using a CdTe target, and the consequent addition a highly oxidizing gas such as N 2 O [2][3][4][5], NH 3 [6] or even N 2 , which catalyses the oxidation of CdTe by means of the residual or added oxygen in the vacuum chamber [1,7,8]. In previous works it was demonstrated that the oxygen incorporation to CdTe changes gradually the tellurium valence from Te − 2 to Te + 4 [2,3], forming amorphous CdTe oxides ranging from a-CdTe:O to aCdTeO 3 .…”