Recombination ina−Si:H: Defect luminescence

A study of defect photoluminescence in $a-\mathrm{Si}:\mathrm{H}$ is presented. In both doped and undoped samples we observe a broad defect-related transition peaking at 0.9 eV with a width of ∼0.35 eV. The line shape, temperature dependence, and excitation energy dependence of this luminescence are described. The recombination is interpreted as a transition between an electron in a doubly occupied dangling bond, and a valence-band tail hole. We estimate that the electron trap depth is ∼0.5 eV and involves a distortion energy of about 0.1 eV. The relation between the luminescence data and light-induced electron spin resonance is also discussed.