Edge photoluminescence of single-crystal silicon with a p-n junction: Structures produced by high-efficiency solar cell technology

Abstract

The systematic features and kinetics of edge photoluminescence of silicon structures produced by the high-efficiency solar cell technology is studied at different voltages applied to the p-n junction. It is shown that the effect of modulation of the edge photoluminescence intensity by a dc voltage applied to the p-n junction is qualitatively similar to the effect induced by excitation of photoluminescence by laser radiation at the wavelengths 658 and 980 nm. The possibility of modulating the edge photoluminescence power by varying the resistance parallel to the p-n junction is demonstrated. It is found that, at zero voltage, the rise time constant of the photoluminescence intensity far exceeds the decay time constant. However, as the dc forward current is increased, the decay time constant approaches the rise time constant. To interpret the results, the concepts of the second, more efficient saturable recombination channel coexisting with the common Shockley-Read-Hall recombination channel in the structure are developed. The study extends the functional capabilities of the luminescence technique in determining the effective lifetimes of charge carriers.