Evidence for the hydrogen-glass model of metastability annealing in phosphorus-doped amorphous silicon

We present qualitative and quantitative evidence that the H-glass model is applicable to metastability annealing in P-doped hydrogenated amorphous silicon and measure the principal parameter of the model. We study the effect of H content on the annealing of quenched-in, metastable, excess dark conductivity in amorphous silicon. The annealing temperature (${\mathit{T}}^{\mathrm{*}}$) is 355±20 °C in sputtered P-implanted amorphous silicon (a-Si) containing 0.1 at. % of H. After hydrogenation with about 10 at. % of H, ${\mathit{T}}^{\mathrm{*}}$ falls to 175±20 °C, much closer to the 130 °C observed in glow-discharge hydrogenated a-Si. We derive a quantitative prediction of the H-glass model: the H-diffusion coefficient at ${\mathit{T}}^{\mathrm{*}}$ is inversely proportional to the H content in a-Si samples. Our measurements of H-diffusion coefficient at ${\mathit{T}}^{\mathrm{*}}$ are in agreement with this prediction.