Fabrication of kesterite absorber films by spray pyrolysis: Effect of annealing temperature on the phase formation

Kesterite thin films have been fabricated by chemical spray pyrolysis technique using less toxic organic solvent followed by annealing at different temperatures in inert nitrogen atmosphere. Phase formation and structural evolution were studied by XRD and Raman spectroscopy. The films annealed at 450°C and 500°C exhibited excellent properties required for photovoltaic absorber materials. UV-Vis spectroscopy was used to estimate absorption coefficient and band gap; the films annealed at 450°C and 500°C showed band gap of 1.65eV and 1.51eV, respectively.  Surface morphological properties and film thickness were studied by FESEM and electrical properties by Hall measurement system. Films annealed at 500°C showed densely packed grains with thickness ~ 1.2μm. Electrical properties of the films annealed in nitrogen atmosphere were in good agreement with the values previously reported for CZTS thin films. Copyright © 2017 VBRI Press