The influence of the exciton non-radiative recombination in silicon on the photoconversion efficiency. 1. Long Shockley–Read–Hall lifetimes

Abstract

By comparison of the experimental dependence of bulk lifetime in silicon on the doping and excitation levels with theoretical calculations, it has been shown that a new recombination channel becomes operative when Shockley–Read–Hall lifetime is below 20 ms and the density of doping impurities or the excess electron-hole pair density is of the order of 10¹⁶ cm⁻³. This recombination mechanism is related to the non-radiative exciton Auger recombination assisted by the deep impurities in the bulk. The influence of non-radiative exciton recombination on the photoconversion efficiency in solar cells has been analyzed. It has been shown that the shorter the Shockley–Read–Hall lifetime, τSHR, the stronger its effect. In particular, for τSHR = 100 μs, this recombination channel leads to the reduction of the photoconversion efficiency by 5.5%.