Ultimate efficiency of cascade solar cells based on homogeneous tunnel-junction structures in CPV systems

High voltage cascade solar cells on the basis of n +-p-p +(t)n +-p-p +(t)…n +-p-p + multilayer structures manufactured from homogeneous type semiconductor with the quantum mechanical tunnelling effect of charge carriers in p +(t)n + junction under concentrated radiation have been studied. The expressions for the theoretical and physical upper-limit values for open circuit voltage and efficiency of cascade solar cell and spectral characteristics, design and physical parameters of cascades have been obtained. Dependencies of the upper-limit efficiency for silicon cascade photovoltaic converters on solar radiation concentration ratio, number of cells and dead layer thickness in cascade tunnel-junction structures have been investigated.