Influence of Annealing Process on Cu2O Nanofilm and the Efficiency of Annealed p-Cu2O/n Si Nanostructure Solar Cell Prepared by Thermal Evaporation Technique

Abstract

Thin film solar cells are one of the significant electronic applications due to their beneficial characteristics, especially adjustable optical features low cost, and high efficiency. In this research, p-type cupric oxide (Cu2O) nanofilms have been successfully deposited onto glass and n-type Si substrates by thermal evaporation technique under 10 -7 mbar, rate of deposition of 0.3 nm/s after that annealed at 200℃. The annealing process leads to an increase in the uniformity and homogeneity distribution of particles on the thin film surface as well as an improvement of the roughness. FE-SEM images of Cu2O nanofilms show that the average size has been increased from 25.15 to 35.36 with the enhancement of the distribution of particles after the annealing process. Average roughness and root mean square have increased from (0.166 to 1.18) nm and (0.213 to 1.490) nm respectively. Electrical characteristics of annealed Al/ Cu2ONPs/Si/Al solar cell were examined by current-voltage measurement. The short circuit current (ISC.) of 15 mA, open circuit voltage (VOC) of 500 mV, fill factor (F.F) of 0.45, and the efficiency (η) was found to be 3.37%. The annealing temperature gives more roughness to the surface and raises the absorption of incident photons and solar cell efficiency.