Fabrication of hydrogenated amorphous silicon films exibiting higher stability against light soaking

Hydrogenated amorphous silicon (a-Si:H) films containing low hydrogen concentrations (Si–H = 4 at.%, Si– ₂ < 1 × 10 ²⁰ cm ⁻³ ) were developed at the substrate temperature of 250 °C. A-Si:H films were fabricated using a triode deposition system, where a plasma generation region and a film growth region are separated from each other. Stability of the a-Si:H was investigated by applying this material to an i-layer of a solar cell. The degradation ratio of the prepared n–i–p solar cell was 7.96% with a stabilized efficiency of 8.09%, while that of the conventionally prepared a-Si:H solar cell was 17.4% with a stabilized efficiency of 7.43%. The result shows promising stability of the triode-deposited a-Si:H having low Si–H ₂ density.