Quantum efficiency analysis of thin-layer silicon solar cells with back surface fields and optical confinement

Thin-layer silicon solar cells utilize surface textures to increase light absorption and back surface fields to prevent recombination at the silicon-substrate interface. We present an analytical model for the internal quantum efficiency that accounts for light trapping and also considers carrier generation and recombination in back surface fields or substrates. We introduce a graphical representation of experimental data, the so-called Parameter-Confidence-Plot, which allows one to draw maximum information on diffusion lengths and surface recombination velocities from quantum efficiency measurements. The analysis is exemplified for state of the art thin-layer silicon solar cells with and without back surface fields.