Optoelectronic properties of spray deposited SnO2:F thin films for window materials in solar cells

• Published in: Journal of Optoelectronics and Advanced Materials Vol. 5; no. 1; pp. 45 - 54
• Main Authors: Elangovan, E, Ramamurthi, K
• Format: Journal Article
• Language: English
• Published: 01.03.2003
• ISSN: 1454-4164

Spray pyrolysis technique has been employed to prepare #~1.2 *mm. thick pure and fluorine doped tin oxide films from SnCl2 precursor. The electrical and optical studies on the as prepared films were carried out. The sheet resistance was found to decrease with increasing doping concentration to a minimum of 1.75 *W/DAL for 15 wt.% of NH4F, but increased thereafter. The minimum sheet resistance observed in the present study is the lowest among the reported values for SnO2:F films prepared from SnCl2 precursor. The transmittance was found to increase with the increase in fluorine concentration. The highest optical transmittance obtained is 85% (at 800 nm). The calculated reflectivity in the infrared region is in the range of 94-98% (for 5-30 wt% NH4F). On fluorine doping, the figure of merit values of the tin oxide films were found to increase to a maximum of 5.67 x 10-2 (15 wt.% of NH4F) from 4.73 x 10-6 (at 800 nm) for undoped ones. The obtained values of figure of merit and reflectivity are discussed in the context of the suitability of this material for transparent and conducting window materials in heterojunction thin film solar cells.