The effects of solvent and dopant impurities on the performance of LPE silicon solar cells

This paper reports the effect of solvent and dopant impurities on the performance of LPE silicon solar cells. For LPE layers grown from Sn and In based solutions and having similar surface morphology and resistivity, the performance of solar cells made on LPE layers grown from In was always higher than that of cells made on LPE layers grown using Sn as solvent. Consistently higher performance was also obtained from solar cells fabricated upon Ga-doped LPE layers than from cells made on Al-doped LPE silicon. The best cell was fabricated upon a Ga-doped LPE layer grown from In solution and had a total area efficiency of 16.4% confirmed by Sandia measurements. The observed phenomena are explained on the basis of Hall mobilities and minority carrier lifetimes of LPE layers grown from different solutions, and also the oxidation difference of these layers during cell processing.