Drift mobility measurements in a-SiN x:H

Abstract

Temperature dependence of the electron drift mobility ( μ d) in a-Si:H, and in a set of three a-SiN x :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 cm 2 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 cm 2 V −1 s −1 . The results confirm that the conduction band tail broadens with an increase of nitrogen content in a-SiN x :H.