Evidence for the void size related IR absorption frequency shifts in hydrogenated amorphous germanium films
Journal
Solid State Communications
Journal Volume
113
Journal Issue
2
Pages
73-75
Date Issued
1999
Author(s)
Chou Y.-P
Abstract
Hydrogenated amorphous germanium alloys (a-Ge:H) have been prepared by plasma enhanced chemical vapor deposition at a substrate temperature of 200°C. The films tend to oxidize as soon as they are taken out from the chamber and exposed to air. The oxidation process is found to follow a percolation channel formed by a continuous linkage of large voids that is evidenced by the observation of the decline of the intensity of Ge-H stretching mode at 1980 cm-1 to zero while the other peak at 1890 cm-1 does not change. This means that the peak at 1980 cm-1 corresponds to the Ge-H stretching mode in large voids while that at 1890 cm-1 corresponds to Ge-H stretching mode in isolated small voids. Thus, the frequency shifts of the stretching mode should arise from the difference of the void size where Ge-H bonds are situated. © 1999 Elsevier Science Ltd. All rights reserved.
Subjects
A. Disordered systems; A. Semiconductors; A. Thin films
SDGs
Other Subjects
Hydrogenation; Infrared radiation; Light absorption; Plasma enhanced chemical vapor deposition; Semiconducting germanium; Hydrogenated amorphous germanium alloys; Semiconducting films
Type
journal article