Hydrogen Distribution in High Stability A-Si:H Prepared by the Hot Wire Technique

Abstract

AbstractIn this work the microstructures of 2–3 hydrogen at.% hot-wire CVD a-Si:H films were characterized by 1H nuclear magnetic resonance (NMR). Significant differences were found between the hydrogen distribution in these samples and that in conventional plasma-enhanced CVD samples. Among other things, the broad resonance line in the hot-wire a-Si:H is 50 kHz wide, which is much broader than that observed 25–35 kHz in PECVD a-Si:H films. Moreover, a 0.5 kHz resonance absorption hole width due to intrinsic dipolar interactions is obtained using the hole-burning technique. Surprisingly, approximately 90 percent of the hydrogen atoms give rise to the 50 kHz line and only a very small percentage of the hydrogen atoms give rise to the much narrower resonance line.