Abstract:
The wide band gap semiconductor materials industry encompasses several oxides. Zinc oxide obtained by pyrolysis spray method has great importance in the industry materials for microelectronic devices. The objective of the present work was to optimize the necessary elaborations conditions
for the formation of thin ZnO layer used as a window layer (TCO) in CZTS solar cell. First, we approached the optimization of the two key parameters (concentration of the solution and substrate temperature) of the undoped ZnO thin films. Furthermore, various analyzing techniques have been used to examine the structure, morphology, composition, optic and electric of the synthesized films. The results showed that the film deposited at 0.1M and
350°C has a low thickness (204 nm), a transmittance greater than (90%) and a wide gap (3.29 eV). Second, we studied the effect of the doping rate on two series of ZnO films produced at 0.1M and Ts = 350 ° C. The first AZO series is doped with aluminum (1%, 3%, 5% and 7.5% and 10%) and the second is FZO series doped with fluorine (1%, 5%, and 7.5%). The obtained
results show that the ZnO film doped from 7.5% aluminum has a large band gap energy (3.44 eV), a high transparency, greater than 90%, low electrical resistivity (50 Ω. cm) and a large merit factor (99 x 10-4 Ω-1).
All these optimized results offer good potential to involve this film as the windows layer in CZTS solar cells. In addition, the optimization of the absorbent layer (using the simulator SCAPS-1D) of the proposed cell (n+ - ZnO / i- ZnO / CdS / CZTS / Mo) without and with a BSF layer of (CZTSe) shows a change in efficiency from 10.4% to 15%.
