A simulation study towards a new concept for realization of thin film triple junction solar cells based on group IV elements

In this paper, the theoretical efficiency of multi-junction solar cells based on group IV elements has been investigated. The effects of different absorbing layer numbers, different band gap combinations, and temperature changes have been reviewed for multi-spectral solar cells. Several simulations were done to identify the ideal band gap combination for triple-junction solar cells. Based on these results and under consideration of actual material parameters, a new promising triple-junction solar cell concept with a-Si:H/mu c-Si:H/ and mu c-Ge:H has been found for developing high efficiency thin film solar cells. Additionally, advanced simulations were performed in order to evaluate the feasibility of this new concept. The photocurrent, the external quantum efficiency, and the layer thicknesses were simulated and evaluated. All parameters deliver promising results for a new triple-junction solar cell concept with an intermediate reflector between the middle- and bottom structure. Copyright (c) 2011 John Wiley & Sons, Ltd.