Characterization of CdSe films prepared by chemical bath deposition method

Metin H., Erat S., ARI M., Bozoklu M.

OPTOELECTRONICS AND ADVANCED MATERIALS-RAPID COMMUNICATIONS, vol.2, no.2, pp.92-98, 2008 (SCI-Expanded) identifier identifier


The optical, structural and electrical properties of Cadmium Selenide (CdSe) thin films were deposited by a simple and inexpensive method, chemical bath deposition (CBD), have been investigated. The optical measurements have been obtained by using the UV-Visible spectrophotometer and the optical band gap energy (E-g) was calculated from the absorption spectra as 1.83 eV and 1.76 eV for the chemically deposited CdSe thin films at 60 degrees C and 70 degrees C, respectively. The samples were characterized by using the X-ray diffraction method, the scanning electron microscope (SEM) and the energy dispersive X-ray analysis (EDX). The grain size of the films depend on the annealing temparature and is situated in the range 86 - 820 angstrom from X-ray analysis. The electrical resistivity and conductivity of the CdSe films have been determined by using four-point probe technique in the temperature range between 310 - 640 K. The electrical resistivities were found in the order of 106 Omega-cm at room temperature and in order of 104 Omega-cm at 640 K. The activation energy was found to be about 0.27 eV - 0.41 eV and the temperature coefficient of electrical resistivity was found to be about -3.04x10(-3) K-1 and -3.27x10(-3) K-1 for room temperature and 640 K, respectively.