Photoinduced expansion in hydrogenated amorphous silicon

Conference · Thu Jul 01 04:00:00 EDT 1999

OSTI ID:20107923

Nonomura, S; Gotoh, T; Nishio, M; Sakamoto, T; Kondo, M; Matusda, A; Nitta, S

The structural aspect of photodegradation effect in hydrogenated amorphous silicon has been investigated by the use of the simple and sensitive detection technique, the laser optical-level bending method, for a small expansion or extraction in thin films. The volume change induced by the thermal expansion due to the photothermal effect and the residual expansion was observed in hydrogenated amorphous silicon prepared by PECVD. The latter residual expansion was persistent after light soaking and was recovered by thermal annealing at 200 C. The time dependence of the volume expansion with light soaking shows the same time dependence of photoinduced defect density. The photoinduced volume changes normalized by the initial volume are the order of 10{sup {minus}6} {approximately} 10{sup {minus}5}, which values are two orders smaller than chalcogenide glasses such as a-As{sub 2}S{sub 3}. The normalized volume change of a-Si:H with the different sample preparation conditions of PECVD such as the hydrogen dilution ratio r (r = SiH{sub 4}/H{sub 2}) and substrate temperature is shown. Also it is demonstrated that the photoinduced expansion is observed in hydrogenated amorphous silicon prepared by photo CVD and hot-wire CVD methods. The spatial extent related to a photoinduced defect creation in a-Si:H is estimated.

• Research Organization: Gifu Univ. (JP)
• OSTI ID: 20107923
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
36 MATERIALS SCIENCE
AMORPHOUS STATE
CRYSTAL DEFECTS
HYDROGEN ADDITIONS
MICROSTRUCTURE
OPTICAL PROPERTIES
SILICON
VOLUME