Electrochemical deposition of Zn3P2 thin film semiconductors on tin oxide substrates

Zn3P2 semiconductor thin films were prepared by electrodeposition technique form aqueous solutions. The deposition mechanism was investigated by cyclic voltammetry technique. Crystal structure, morphology and composition of as deposited and annealed Zn3P2 thin films grown on SnO2/glass substrates were determined by X-ray diffraction, scanning electron microscopy, and energy dispersive X-ray analysis. X-ray diffraction data indicated the formation of Zn3P2 as the predominant phase for both as-deposited and annealed films. The compositions of the deposited films were controlled by the bath temperature, deposition potential and Zn/P ratio in the solution. The dark current-voltage measurements of SnO2/Zn3P2/C devices indicated a rectifying behavior and a reverse saturation current density of 1.7 x 10(-7) A/cm(2) which is in good accordance with that obtained from films prepared using vacuum technique. Also, the capacitance-voltage measurements showed that the number of interface states and the built in potential are in the order of 5 x 10(-9) cm(-3) and 0.85 V, respectively. These preliminary results for Zn3P2 thin films reveal that, this semiconductor material can be used for solar cell applications. (c) 2005 Elsevier Ltd. All rights reserved.