Drift mobility measurements in a-SiNx:H

Temperature dependence of the electron drift mobility (μd) in a-Si:H, and in a set of three a-SiNx:H alloys has been determined from the steady-state photoconductivity and response time measurements. The activation energy of the a-Si:H is found to be 0.11 eV and calculated drift mobility is ∼0.1 cm2 V−1 s−1 at room temperature. While the activation energy of the alloys increases up to 0.25 eV with increase of nitrogen content and for the sample with the highest N content, the room temperature drift mobilty decreases to ∼2.4×10−6 cm2 V−1 s−1. The results confirm that the conduction band tail broadens with an increase of nitrogen content in a-SiNx:H.