Ion beam rehydrogenation and post-hydrogenation of a-Si:H

Abstract

We have studied the rehydrogenation and post‐hydrogenation of a‐Si:H using a Kaufman ion beam source. The achievement of an air‐mass‐one (AM1), photo‐to‐dark conductivity ratio of 5.6×10⁵ with a rehydrogenated a‐Si:H sample was reported earlier [Y. S. Tsuo, E. B. Smith, and S. K. Deb, Appl. Phys. Lett. 5 1, 1436 (1987)]. In this communication we report recent results of the rehydrogenation study and new results of a study of the post‐hydrogenation of amorphous silicon deposited by glow discharge at 480 °C. AM1 photo‐to‐dark conductivity ratios as high as 9.5×10⁶ (with a photoconductivity of 8.6×10⁻⁶ Ω cm⁻¹) and 1.1×10⁵ (with a photoconductivity of 6.3×10⁻⁶ Ω cm⁻¹) have been obtained with a rehydrogenated sample and a post‐hydrogenated sample, respectively. We also report the results of the hydrogen depth profile and photostability measurements of these samples.