IV characteristics of ITO/Cu2O/ metal junctions

Abstract

Cuprous oxide is an inexpensive and non-toxic semiconductor material having the potential for use in low-cost photovoltaic devices. Electrodeposition is a low-cost method t0 produce thin Cu2O films and electrodeposited CU2O has been reported to be n-type, In order to investigate the possibility of using electrodeposited Cu2O in solar cells, Cu2O/metal junctions were studied using their I-V characteristics. Thin films of Cu20 were electrodeposited on Indium tin oxide (ITO) coated glass substrate using an aqueous solution of cupric acetate. Electrodeposition was carried out under potentiostatic condition of -250 mV vs SCE at 55"C for a period of 1 h. These Cu20 samples were used to make junctions with Al, Hg,Cu, Ag and Au. The I-V plots of these junctions were obtained in dark and when illuminated. The I-V characteristics of the Cu2O/Hg junction show good rectifying properties.The plots for the junction in dark and under illumination indicate that the electrodeposited Cu2O behaves as an n-type semiconductor. The I-V profile fits into the standard diode equation with I0 = 2.8 x 10 -10 A, ideality factor n=0.48 and series resistance Rs = 40U. Also, the Junction exhibits a contact potential of about 150 mV.