Effects of inhomogeneous grain size distribution in polycrystalline silicon solar cells

We investigate the effects of grain size inhomogeneity on the performance of thin film polycrystalline silicon solar cells with columnar grains. We focus on cells with an exponential distribution of the grain diameter, which approximates the grain size inhomogeneity in polycrystalline silicon films made via aluminum induced crystallization (AIC) with low temperature annealing. Through equivalent circuit simulation, we demonstrate that the size inhomogeneity will only play a role when intra grain defects, which is common in AIC cells, can be avoided. We further demonstrate that the inhomogeneity itself is not a dominant factor which limits the efficiency of these cells.