Investigation of the thermal behaviour of thin crystalline silicon solar cells

This paper investigates the thermal behaviour of thin crystalline silicon solar cells and determines whether the decrease in cell thickness affects the temperature dependences of the solar cell parameters. For the investigation crystalline solar cells with different photoactive layer thicknesses were processed. Sample cells were formed on n+-substrate wafers with n epitaxial layers where due to the low minority carrier lifetime in the n+-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 dependence the solar cell parameters were determined. Most of the parameters showed no differences in their temperature behaviour, but the temperature dependence of the short circuit current and the fill factor differed on all sample cells. 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 could be of interest in sensor applications, e.g. for the thermal compensation of light sensors.