Further Results in the General Theory of Barrier Layer Rectifiers

It is pointed out that the temperature variation VD=a-bT of the diffusion potential, as deduced from the forward characteristic of rectifiers, is in broad agreement with theory. Hence formulae are derived for the temperature variation of the zero resistance of a rectifier having an arbitrary distribution of impurity centres, and subject to either diode or diffusion theory Interpretation of experiments with the aid of these formulae leads to the temperature dependence of (a) the effective mass of current carriers in germanium rectifiers, and (b) of the mobility of current carriers in selenium rectifiers The latter curve has the same form as that obtained from Hall effect measurement, and it is pointed out that it is of broadly the same shape as the corresponding curves for high resistivity samples of silicon and germanium It is shown that two d c characteristics of the same rectifier, but corresponding to different temperatures, can intersect Formulae for the applied voltage and the temperature rise which lead to the onset of thermal instability are deduced for all impurity centre distributions, and for diode and diffusion theory A general theory of current creep in rectifiers is outlined, and good agreement obtained with experiments on selenium rectifiers