Detailed accounting for quantum efficiency and optical losses in a-Si:H based solar cells

Abstract

By using TCO front contact layers with increasing haze, but constant "true" absorbance, the effect of light scattering on the generated solar cell current can be evaluated independently of usually compensating effects. The increase in light scattering results in a higher quantum efficiency, due to increased light trapping and reduced reflectance at the TCO/p-layer interface, but also in higher optical losses, due to increased absorbances in the nonphotoactive layers, and multiple reflections at the back reflector. The difference between the effective transmission of the TCO and the quantum efficiency represents the optical losses that are individually accounted for. The analysis is based on measurements that for proper accounting are required to be performed on the same area portions of the glass/TCO substrate and subsequently deposited cells.