Papers Published

  1. Leo, P.H. and Moore, K.D. and Jones, P.L. and Cocks, F.H., Positron annihilation studies of Si, a-Si, and a-Si:H using Doppler broadening techniques, Phys. Status Solidi B (East Germany), vol. 108 no. 2 (1981), pp. 145 - 9 .
    (last updated on 2007/04/10)

    Abstract:
    Positron annihilation method has been used to probe the nature of defect states in a-Si and a-Si:H. Multiple S-parameter determinations performed using c-Si, a-Si, and a-Si:H reveal a difference in the observed Doppler broadened positron annihilation γ-energy spectra. Compared to the S-parameter obtained for crystalline silicon, a systematic increase in the S-parameter was noted for a-Si:H and a-Si, with a-Si exhibiting the largest value. A positive correlation between Ns, the number of unpaired electron spins determined by ESR spectroscopy, and the corresponding S-parameter for c-Si, a-Si, and a-Si:H implies an association between electronic defect states and lattice defect states

    Keywords:
    amorphous semiconductors;defect electron energy states;Doppler effect;elemental semiconductors;hydrogen;positron annihilation in liquids and solids;silicon;