One-Carrier Space-Charge-Limited Current in Solids

Abstract

The one-carrier, trap-free space-charge-limited current is calculated and the general solution is given in the form of a computed, normalized voltage-current curve. Both diffusion and drift currents are considered. The result is then compared with the widely used J ∝ V2 expression and it is shown that this relation is valid for voltages greater than 100 kT/q. The contradictions arising in the J ∝ V2 derivation are clarified. Finally, the carrier transit time through the space-charge-limited region is given.