DIFFERENCES BETWEEN AMORPHOUS AND NANOSTRUCTURED SILICON FILMS AND THEIR APPLICATION IN SOLAR CELL

摘要

Nanostructured silicon thin films were produced in a single PECVD (Plasma Enhanced Chemical Vapour Deposition) reactor using an excitation frequency of 27.12 MHz. The process parameters were selected to allow the films' production to be performed at the transition region (from amorphous to microcrystalline), aiming their use in solar cells. The real and imaginary parts of pseudo-dielectric function of these nanostructured films show a shift to higher energies and the order factor reveals an improvement on the short atomic range order of the films produced. The solar cells with a structure of ZGO/p-a-SiC:H/buffer_(1)/buffer_(2)/i-(nc/a-Si:H)-a-Si:H/Ag/Al were deposited with nanostructured intrinsic layer, showing a good performances, with current densities of about 14.48 mA/cm~(2), open circuit voltage of 0.94 V, and fill factor of 0.67, which lead to efficiencies of 9.12percent. The solar cell degradation study performed under AM1.5 spectrum conditions up to 100 hours revealed a decrease on the solar cell efficiency of about 8.11percent, mainly related to the decreasing of current density. Despite that, the open circuit voltage increases slightly after the degradation.