Temperature dependence of the optical transitions in electrodeposited Cu2Othin films

Cu2O films on flexible copper and molybdenum (Mo) substrates were prepared by electrodeposition form an alkaline bath. The as-deposited films were p-t ype and the XRD analysis revealed that the film contains only the Cu2O phas e. The thickness of the films was calculated from the interference fringes in the reflection spectra. The Au/Cu2O Schottky diodes were prepared by spu ttering a 15 nm thick layer of very pure gold onto the Cu2O films on Mo sub strate. The probable optical transitions near the band edge were calculated from the spectral response of the device. The band gap calculated at vario us temperatures show a linear dependence on temperature and the absolute ze ro value of the band gap is deduced as 2.206 eV. The 2.493 eV direct transi tion observed in the room temperature shows a temperature dependence. Evide nce of phonon assisted indirect transitions were observed at various temper ature regions. (C) 2001 Elsevier Science BN. All rights reserved.