Chemical deposition and characterization of Cu3Se2 and CuSe thin films

A chemical deposition method for fabrication of Cu,Se, and CuSe thin films is presented. The films' growth is based on the decomposition of selenosulf ate in alkaline solution containing a copper(II) salt and a suitable comple xing agent. The deposited materials were identified by X-ray diffraction. I n addition, optical investigations were performed, The absorption onset in the optical spectra of the annealed Cu3Se2 films showed a slight red shift (compared to the as-deposited ones), indicating a very slight increase in t he average crystal size, The optical (direct) band gap energy of Cu3Se2 thi n films is 2.37 eV, while the CuSe thin films are characterized with two di rect band gap energies of 2.0 and 2.8 eV, The average crystal size values, calculated on the basis of the recorded XRD patterns, are approximately 40 nm for both Cu3Se2 and CuSe thin films. (C) 2001 Academic Press.