Luminescence in Amorphous Silicon p-i-n Diodes under Double-Injection Dispersive-Transport-Controlled Recombination

The temperature and electric-field dependence of the forward bias current and the electroluminescence (EL) in hydrogenated amorphous silicon (a-Si:H) p-i-n and n-i-p diodes have been studied. Both the current and the EL efficiency temperature dependence show three regions depending on either hoping-controlled or multiple-trapping or ballistic transport mechanisms. Comparing thethermalization-controlled geminate recombination processes of photoluminescence to the features of EL, the differences can be explained by transport-controlled nongeminate recombination in trap-rich materials.