Optimized Interdigitated Back Contact (IBC) solar cell for high concentrated sunlight

A one-dimensional analytical model for Interdigitated Back Contact solar cells (IBC), also applicable to Front Surface Field (FSF) and Tandem Junction (TJ) solar cells, is presented. The quantum efficiency, generation current, dark current, and conversion efficiency are calculated as a function of the physical parameters of the cell (doping levels, junction depths, thickness, and lifetime). The proposed model simulates the response of FSF and TJ solar cells more accurately than models using the concept of effective surface recombination velocity. The optimization of parameters (doping level and dimension of each region) is discussed. It is shown that a conversion efficiency of 24.8 percent can be reached under 50 suns. IBC solar cells were fabricated with different substrate resistivities and thicknesses. The experimental results are compared to the theoretical predictions.