Temperature dependence of radiative and non-radiative lifetimes in hydrogenated amorphous silicon

Abstract

The recombination lifetimes of hydrogenated amorphous silicon (a-Si:H) are studied as a function of temperature by transient photoluminescence (TPL). The decay curves in the time regime 2 ns to ≈ 100 ms are transformed into lifetime distributions (LTD). At 10 K we observe two peaks in the LTD at ≈ 2 ms and ≈ 1 μs. Increasing the temperature results in a broadening of the LTD, showing evidence for a third peak. This component exhibits a temperature dependent peak position and dominates the LTD for T < 120 K. Since the decrease of this lifetime with temperature matches the decrease of the steady state PL signal we identify it as being representative of a mainly non-radiative recombination channel.