Growth temperature and microstructural differences in hydrogenated amorphous silicon deposited on glass substrates

Hydrogenated amorphous silicon (a-Si:H) is an important thin film semiconductor with a wide variety of applications in microelectronics and optoelectronics. However, it is metastable and photodegrades after a moderate light illumination (Staebler-Wronski effect). The most stable material has been suggested to be at the edge of crystallinity with microcrystalline inclusions. Using a combination of positron annihilation and X-ray diffraction techniques, the microstructure of hydrogenated amorphous silicon grown by hot wire chemical vapour deposition on glass substrates at different substrate temperatures ranging between 300°C and 500 °C is examined. In previous studies the crystallisation was accompanied by a relaxation of defect structure with an increase in free volume at positron annihilation site. In this work, both techniques show a relaxation of the network with increasing growth temperature, leading to a higher degree of ordering, shorter bond lengths, and a reduction in the average size of defects in the material.

Grantor dc:publisher.institution

Department of Physics

Year dc:date.issued

2002

Author dc:creator

• Minani, Evariste

Advisors dc:contributor.advisor

• Härting, Margit
• Britton, David T

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/11427/6995

OAI identifier oai:identifier

oai:open.uct.ac.za:11427/6995