Recombination in amorphous SiN_x: H alloys

Abstract

Photoluminescence and optically detected magnetic resonance measurements have been used to characterize the recombination processes in a-SiN_x: H alloys. A quenching signal near g=2 is explained in terms of non-radiative recombination involving dangling bonds and two tail states, including a component at g=2.01, similar to that in a-Si, with a width which increases with nitrogen content. A broad enhancing signal at g=2 also resembles that seen in a-Si: H, with a width dependent on nitrogen content. Its origin is not yet clear. A signal at g=4 has been assigned to a triplet excitonic recombination process analogous to that proposed for a-Si_xC_1−x: H. The importance of silicon dangling bonds in recombination confirms the predictions of the Robertson–Powell defect model.