Field Effect in a‐Si:H Films. Influence of Annealing and Light Exposure

The field effect is studied in undoped glow discharge deposited a‐Si:H films. The reproducibility and reliability of the method is examined. The density of states is calculated using a new scheme which computes the charge density without explicit solution of Poisson's equation from the experimental field effect characteristics. The density of states near the gap center is raised by annealing and light exposure from below 10 17 to about 10 18 cm −3 eV −1 .