JOURNAL OF OPTOELECTRONICS AND ADVANCED MATERIALS, vol.9, no.7, pp.2217-2226, 2007 (SCI-Expanded)
In this work, SnO2 films, belonging to the transparent conducting oxides family and commonly used in photovoltaic solar cells and opto-electronic devices, were deposited by ultrasonic spray pyrolysis technique onto glass substrates at different substrate temperatures of 200, 250, 300 and 350 +/- 5 degrees C. The effect of the substrate temperature on the structural, surface, optical and electrical properties of the produced films was investigated. The structural properties such as crystallinity level, grain size and half peak width were analyzed by using x-ray diffraction patterns. The surface properties and elemental distributions were characterized using scanning electron microscopy and energy dispersive x-ray spectroscopy, respectively. The optical properties like transmission, reflection, absorption and refractive index were investigated depending on the substrate temperature, and the optical band gaps were calculated using optical method. The electrical conduction mechanisms of the films were investigated using current voltage characteristics and the electrical conductivities were calculated with two-probe technique. Also, the energies of donors and donor-like traps were determined from ln sigma similar to 1000/T graphs. After all investigations, it was determined that the structural, optical, electrical and surface properties strongly depend on the substrate temperature, and especially SnO2 films obtained at a substrate temperature of 250 +/- 5 degrees C have desired characteristics for solar cell applications.