Title :
The saturation behaviour of metastable defect creation in a-Ge:H investigated by keV-electron irradiation
Author :
Scholz, A. ; Schroder, B. ; Oechsner, H.
Author_Institution :
Dept. of Phys., Kaiserslautern Univ., Germany
Abstract :
We report on the stability of differently prepared high quality a-Ge:H using keV-electron irradiation as a fast and strong degradation technique for the creation of metastable defects. The influence of film properties on the saturation defect density is carefully studied and a chemical equilibrium model developed for a-Si:H is successfully applied to a-Ge:H. This allows to calculate the saturation defect density of a-Ge:H from its initial film properties. Analysing the chemical equilibrium the influence of specific parameters like hydrogen content and Urbach energy on the saturation defect density after keV-electron irradiation is examined and proposals for the improvement of the stability of a-Ge:H against metastable defect creation are made and experimentally confirmed. The experiments reveal no indication for a principally different stability behaviour of a-Ge:H compared to a-Si:H
Keywords :
amorphous semiconductors; chemical equilibrium; electron beam effects; elemental semiconductors; germanium; hydrogen; Ge:H; H content; Si:H; Urbach energy; a-Ge:H; a-Si:H; chemical equilibrium model; degradation technique; film properties; keV-electron irradiation; metastable defect creation; metastable defects; saturation behaviour; saturation defect density; stability; Absorption; Chemical analysis; Degradation; Electrons; Germanium; Hydrogen; Metastasis; Optical films; Photovoltaic cells; Stability;
Conference_Titel :
Photovoltaic Specialists Conference, 1993., Conference Record of the Twenty Third IEEE
Conference_Location :
Louisville, KY
Print_ISBN :
0-7803-1220-1
DOI :
10.1109/PVSC.1993.347100
