Electron irradiation effects on the properties of heavily phosphorus-doped a-Si : H films prepared from undiluted silane

The effects of 1.0 MeV electron irradiation on the dark conductivity and amorphous network of heavily phosphorus-doped a-Si : H films have been studied. The electron irradiation leads to a strong decrease by about two orders of magnitude in the dark conductivity of heavily phosphorus-doped a-Si : H films and the degradation comes to a saturation. The evolutions of the amorphous silicon network of heavily doped a-Si : H films caused by electron irradiation were investigated by Raman spectroscopy. The observed decrease in the amorphous silicon network order in the short and intermediate range suggests that the electron irradiation induces structural defects in the films. This defect creation also tends to saturate after a long irradiation time.