Conductivity effects in hydrogenated amorphous silicon induced by gamma-ray irradiation

✍ Scribed by S. Baccaro; G. De Cesare; G. Maiello; G. Masini; M. Montecchi; M. Petti; A. Ferrari

• Publisher: Elsevier Science
• Year: 1996
• Tongue: English
• Weight: 235 KB
• Volume: 31
• Category: Article
• ISSN: 0925-4005
• DOI: 10.1016/0925-4005(96)80024-4

✦ Synopsis

Hydrogenated amorphous silicon films 0.45 and 1.12/~m thick, grown by RF glow discharge plasma PECVD on Coming-7059 glass, were irradiated by a 6°Co source (activity 2.8 × 1015 Bq) in the dose range 10-450 kGy at different dose rates. The dark current of the samples, under 100 V appfied voltage, was measured before, during and after gamma irradiation. When the irradiation starts, the dark current increases up to a level linearly dependent on the dose rate. When the irradiation is switched off, the dark current returns close to the initial value in a few days. Such behaviour suggests a possible application of hydrogenated amorphous silicon films in dosimetry and as gamma ray sensors. Moreover, the film optical constants were computed from the transmittance spectra measured in the range 500-2500 nm, before and after irradiation. After irradiation, the film optical absorption is slightly increased and the energy gap is substantially unchanged.