Hole carrier drift-mobility measurements in a−Si:H, and the shape of the valence-band tail

摘要: Abstract A detailed study has been performed concerning the temperature and electric-field dependence of hole carrier time-of-flight pulses in amorphous silicon. Various aspects experimental behaviour are employed estimation energy distribution other characteristics localized states films. Over depth range 0·2 to 0·45eV, trap concentration is found vary more rapidly than exponential form assumed earlier studies, a Gaussian tail better agreement with data. Localized-state capture cross-sections calculated as 1–3 × 10−16 cm2, essentially independent over studied. Taking present data conjunction determined by techniques allows an mobility free holes. The value about 10cm2V−1s−1 thus obtained order magnitude larger previous estimate from measurements, but comparable figures suggested ...