Published online by Cambridge University Press: 26 February 2011
We measured the diffusion coefficient of H in a-Si:H between 36°C and 690°C via H2-evolution and the pressure rise in a closed ampoule. Our measurement temperatures reached ∼110°C above the highest T reported to date. The diffusion coefficient for unalloyed a-Si:H, DH=1.66×10−3 exp [−1.45 eV/kT] cm2 s−1, agrees with the earlier, lower-T, measurements. Between 250°C and 690°C the H-diffusion mechanism in a-Si:H appears to remain the same, with DH ranging from 10−17 cm2s−1 to 10−10cm 2s−1.