NANOCRYSTALLINE DOUBLY DOPED TIN OXIDE FILMS DEPOSITED USING A SIMPLIFIED AND LOW-COST SPRAY TECHNIQUE FOR SOLAR CELL APPLICATIONS

A simplified and low-cost spray technique using perfume atomizer is employed for the fabrication of nanocrystalline antimony + fluorine doped tin oxide films (SnO2: Sb:F) from aqueous solutions of SnCl2 precursor. The structural studies showed that the grain size of the films increases from 32 nm for undoped film to 71 nm for doubly doped films. The AFM images depict that the films are homogeneous and uniform. The optical transmittance in the visible range is 76 % and the optical band gap is 3.55 eV. The sheet resistance is found to be minimum (4.74 Omega/square) for the doubly doped film, for which doping levels of Sb and F are 2 and 40 at. % respectively. This value is lesser than those reported by many researchers for fluorine or antimony doped tin oxide films by employing different versions of spray pyrolysis technique. The films fabricated by the simplified technique have desirable figure of merit (1.36x10(-2) (Omega/sq)(-1)) comparable with their conventional spray counterparts. Hence this simplified and in-expensive spray technique may be considered as an economic alternative to the conventional spray method for the mass production of solar cell TCO layers and transparent electrodes for optoelectronic devices.