Cr-MIS Solar Cells Using Thin Epitaxial Silicon Grown on Poly-Silicon Substrates

Cr-MIS solar cells were fabricated on 18–30 µm epitaxial-Si layers grown on poly-Si substrates. Solar conversion efficiency values ranged from an average of 8.8% to 4.0% depending on choice of substrate. Nonuniformity of certain substrates led to low efficiency values. Interface state density > 5 × 1012/cm2-eV contributed to low Voc and high n-factor. Low minority carrier diffusion length caused Jsc to drop to 60% of the optimum value. Substrates with imperfections caused an increase in dark current density by three orders of magnitude, which served to decrease photovoltaic response. The procedures given herein could lead to a low-cost solar cell for terrestrial applications.