Current‐stress induced asymmetry in hydrogenated amorphous silicon n‐i‐n devices

摘要: A novel manifestation of carrier induced degradation α‐Si:H is presented. Amorphous silicon n‐i‐n devices, which have been subjected to severe constant‐current bias stress, show a strongly decreased ohmic conductivity. At the same time, J–V characteristics in space‐charge limited regime pronounced asymmetry between ‘‘forward’’ and ‘‘reverse’’ directions. Annealing without bias, restores initial symmetrical characteristics. The decrease conductivity interpreted as due an increased density deep (dangling bond) states lower part band gap within i layer, resulting from thermal equilibration with trapped electrons conduction tails. formation spatially inhomogeneous distribution dangling bond upper half gap, by re‐equilibration holes valence‐band tail ...