Injection-dependent non-radiative SRH recombination via interstitials and dislocations in multicrystalline Si

This paper deals with models of NR carrier recombination in mc-Si, which limits the efficiency of photovoltaic conversion. Experimental minority lifetimes in Si show a variety of dependences on injection levels. Models of non-radiative recombination in silicon were proposed for point defects (e.g., Fe interstitials) and extended defects (e.g., dislocations). High-resolution measurements of carrier transport are technically difficult, so models are used instead to relate carrier recombination processes in mc-Si to minority carrier lifetimes. While the SRH recombination due to shallow and deep point defects may result in a lifetime dependence on concentration with a distinct maximum, the recombination via arrays of dislocations leads to a monotonically increasing lifetime with the carrier concentration.

[1] D. J. Mbewe, D.J. Thomson, R.D. McLeod, H.C. Card, “High-injection conditions at dislocations in silicon: a mechanism for dependence of lifetime on photogeneration rate,” IEEE Trans. on Electron Devices, 31, 5, 523-527 (1984).
[2] J. Schmidt, “Temperature- and injection-dependent lifetime spectroscopy for the characterization of defect centers in semiconductors,” Appl. Phys. Lett., 82, 2178 (2003).