ANALYSIS OF THIN SILICON SOLAR-CELLS FOR HIGH-EFFICIENCY

A comprehensive theoretical analysis taking into account the contribut ion from both the emitter and base regions having finite surface recom bination velocity has been developed for computing short-circuit curre nt, open-circuit voltage, and efficiency of thin AR coated thin silico n solar cells with textured front surface. The dependence of efficienc y on the front surface and back surface recombination velocities and o n the cell parameters have been investigated in details for varying ce ll thickness considering the effects of bandgap narrowing and Auger re combination in the material. It is shown that efficiency exceeding 24% can be attained with silicon solar cells having thickness as low as 2 5 mu m provided both front and back surfaces are well passivated (S < 10(3) cm/s) and the doping concentration in the base and emitter are i n the range of 5x10(16) to 10(17) cm and 10(18) to 5X10(19) cm(-3) res pectively. It is also shown that an efficiency of about 23% can be obt ained for thin cells of 25 mu m thickness with a much inferior quality materials having diffusion length of about 40 mu m.