Spray Pyrolyzed Fluorine-Doped Tin Oxide (SnO2:F) Thin Films for Solar Cell Applications

The present work is focused on the deposition of conducting and transparent fluorine (F)-doped tin oxide, SnO2:F (FTO) films by using spray pyrolysis technique at different substrate temperature (T-s) varying from 400 to 525 degrees C in a step of 25 degrees C and stannic chloride (SnCl4 center dot 5H(2)O) and ammonium fluoride (NH4F) as precursor materials. The structural, optical and electrical properties of resultant FTO films are investigated as a function of substrate temperature (T-s). The resultant FTO films are characterized by using X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), energy dispersive analysis of X-rays, surface profilometer, UV-Visible spectroscopy and Hall Effect measurement. The structural analysis indicated the preferred orientation along [200] direction with pure tetragonal symmetry in the resultant FTO films. The crystallinity of films is noted to be improved with increasing T-s. The values of thickness of FTO films are observed to be between 208 nm and 845 nm. The SEM results indicated nanocrystalline nature of FTO films with average particle size in the range of 18-27 nm. The Hall Effect measurements showed the lowest sheet resistance = 16.04 Omega and better mobility of majority charge carriers (mu) = 22.04 cm(2)/Vs for the films deposited at 425 degrees C. The UV-visible spectroscopic studies showed the highest average transmittance = 88.92% in the visible region (lambda = 400 to 800 nm) for the films deposited at 425 degrees C. All above results indicates that FTO films deposited in present work are useful in solar cell device fabrication applications.