Thermal noise in double injection diodes operating in the insulator regime

Abstract

Thermal noise calculations, based on the Langevin procedure, are given for a double injection diode operating in the insulator regime. The frequency range is restricted to frequencies smaller than the reciprocal free carrier transit times. It turns out that at high frequencies the spectral density of the ac short circuit current fluctuations can be described by Nyquist's formula. At low frequencies an additional term, proportional to (1+ω2τ2)−1 was found, where τ is the hole life time. The low frequency thermal noise level may be some orders of magnitude larger than the level at high frequencies. It is shown that in general the frequency dependent term will be masked by generation recombination noise. A special case is indicated where those contributions become comparable.