Space-charge-induced negative resistance in avalanche diodes

With a realistic and accurate model and the use of numerical techniques to solve the diode equations, it is shown that certain p⁺-n-n⁺diodes exhibit a static negative resistance that is due to space-charge effects. The magnitude of this resistance and the value of current density at which negative resistance appears depend on several device parameters. The dependence of the diode characteristics on these device parameters is presented for several examples. The characteristics of these devices at high frequencies are also discussed, and the possibility of high-powers high-efficiency operation as an oscillator is briefly treated.