Picosecond photoinduced transmission associated with deep traps in phosphorous doped α-Si:H

Photoinduced transmission was observed in the picosecond time domain in phosphorusdoped a-Si:H and connected with deep hole traps produced by doping. The hole transport was found to be dispersive starting before 5 ps and temperature dependent. This shows that the energy distribution of shallow traps is exponential beginning below 10-2 eV from the valence-band top. The deep traps are negatively charged defects, the trapped holes are removed from the recombination process, and their distribution peaks at 0.45 eV above the valence-band top.