| Popis: |
Combined measurements have been made of surface recombination velocity, surface photo-voltage, and the modulation of surface conductance and surface recombination velocity by an external field, on etched germanium surfaces. Two samples, cut from an n-type and a p-type crystal of known body properties, were used, the samples being exposed to the Brattain-Bardeen cycle of gaseous ambients. The results are interpreted in terms of the properties of the surface space-charge region and of the fast surface states. It is found that the surface barrier height, measured with respect to the Fermi level, varies from −0.13 to +0.13 volts, and that the surface recombination velocity varies over about a factor of ten in this range. From the measurements, values are found for the dependence of charge trapped in fast surface states on barrier height and on the steady-state carrier concentration within the semiconductor. |
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