Synthesis and characterization of pulsed laser deposited SnO2-Fe2O3 composite thin films for TCO application

SnO2-Fe2O3 composite thin films were deposited on quartz substrate at 650 °C by pulsed laser deposition with Fe2O3 content varying between 0 and 50 wt.%. The effect of increasing Fe2O3 content on structural, optical and electrical properties of SnO2-Fe2O3 films were investigated. X-ray diffraction analysis indicates that the nature of deposited composite films can be tune from crystalline to amorphous with increase in the Fe2O3 content. X-ray photoelectron spectroscopy studies confirm the presence of SnO2 and Fe2O3 in the microstructure. Atomic force microscopy studies of the deposited films indicate that RMS roughness vary between 114.4 and 1.48 nm. The average optical transmittance decreases from 92 to 72% with increasing Fe2O3 content of the deposited films. The optical bandgap was decreased from 3.69 to 3.31 eV with increase in Fe2O3 content. The minimum resistivity was observed 3.71 × 10−2 Ω cm for the 30 wt.% Fe2O3 composite film. The low resistivity and high transmittance in the visible region enables these films suitable for optoelectronic applications.