Fast nonradiative recombination in sputtereda-Si: H

From measurements of the time decay of the relative luminescence efficiencies of samples of sputtered $a$-Si: H with different defect densities, we identify two low-temperature ($T\sim 80$ K) nonradiative recombination processes. In contrast with previously published analyses, we propose that the nonradiative recombination process most important in determining the steady-state luminescence efficiency at low temperature occurs for $t<\mathrm{}10\mathrm{}$ ns and does not compete on the same time scale with the radiative transition.