Characterization of radiative recombination in amorphous silicon by optically detected magnetic resonance: Part I

Abstract

We present the first detailed comparison of optically detected magnetic resonance (O.D.M.R.) data for sputtered and glow-discharge a-Si: H. Three distinct luminescence processes are inferred for both materials, near 1·4, 1·25 and 0·9 eV. The 1·4 eV emission shows a quenching resonance which can be associated with a non-radiative shunt process between deep electron (g ∼ 2·005) and hole (g ∼ 2·013) tail states. The bands near 1·25 and 0·9 eV show strong enhancing O.D.M.R. signals. We propose a recombination model in which the 1·4 eV emission is due to close pairs, and the 1·25 and 0·9 eV bands are due to recombination of distant pairs. The 0·9 eV peak is associated with dangling-bond defects. The O.D.M.R. g values imply that the 1·25 eV emission is also associated with dangling bonds, but recombination at tail states cannot be excluded.