Thermal Behavior of Crystalline Thin Film Silicon Solar Cell

The goal of this paper is to investigate the thermal behavior of crystalline thin film silicon solar cells, and to determine whether the decrease in cell thickness affects the temperature dependences of the solar cell parameters. For the investigation crystalline solar cells with a photoactive layer thickness of 26, 38 and 50 microns were processed. Sample cells were formed on n+-substrate wafers with n epitaxial layers where due to the low minority carrier lifetime in the substrate only the epitaxial layer participates effectively in the photocurrent generation. The thin photoactive layers were achieved by the etching of the epitaxial layer. On the samples I-V curves and spectral response functions were measured at different temperatures, and the temperature coefficients of the short circuit current, the open circuit voltage and the efficiency were determined. Most of the parameters showed no differences in their temperature behavior, but the temperature dependence of the short circuit current differed on all three sample cells and was in correspondence with the changes of the temperature dependences of the spectral responses. From the results it can be concluded, that decreasing the thickness of the solar cells will have practically no effect on the temperature dependence of the performance and the efficiency of crystalline silicon solar cells. However the dependence of in the temperature coefficients for the short circuit currents on the thickness of the photoactive layer currents could be of interest for sensor applications, e.g. for the thermal compensation of light sensors.