Determination of the electric field profile in amorphous Si diodes

An evaluation method is presented which is applied to the delayed-field time-of-flight (DF TOF) experiment, which allows the determination of the electric field profiles in amorphous-silicon-based devices. It is called differential delayed field (DDF) method. The field profiles at the p/i junction of differently prepared pin-structures were determined. A linearly decreasing phosphorus (P) doping layer was incorporated into the i-layer starting at the p/i junction. The data show that an increased width of a P-profile reduces the carrier injection and hence the electric field strength. The space charge field of a Schottky/a-Si:H contact is studied in dependence of the applied DC bias voltage