Electron drift mobility in hydrogenated amorphous Si_1−xC<i>_x</i>with a low carbon content

Abstract

Abstract The temperature dependences of the electron drift mobility μd in hydrogenated amorphous silicon (a-Si:H) and in a set of four hydrogenated amorphous Si1−xC x (a-Si1−xC x :H) alloys with x ≤ 0.1 has been determined from steady-state photoconductivity and response time measurements. The temperature dependence of the μd curve of a-Si: H shows a region with a single activation energy of 0.13 eV between 150 and 300 K, and an electron drift mobility of about 1 cm2 V−1 s−1 at 300 K. For the alloys, the single-activation-energy region is steeper and moves to higher temperatures. The results confirm that the conduction-band tail widens rapidly with increasing x in a-Si1−xC x :H.