Method for Optimizing the Parameters of Heterojunction Photovoltaic Cells Based on Crystalline Silicon

摘要

An approach is proposed to calculate the optimal parameters of silicon-based heterojunction solar cells whose key feature is a low rate of recombination processes in comparison with direct-gap semiconductors. It is shown that at relatively low majority-carrier concentrations (N-d similar to 10(15) cm(-3)), the excess carrier concentration can be comparable to or higher than N-d. In this case, the efficiency eta is independent of N-d. At higher N-d, the dependence eta(N-d) is defined by two opposite trends. One of them promotes an increase in eta with N-d, and the other associated with Auger recombination leads to a decrease in eta. The optimum value N-d approximate to 2 x 10(16) cm(-3) at which. of such a cell is maximum is determined. It is shown that maximum eta is 1.5-2% higher than eta at 10(15) cm(-3).