Current Transients in the Insulator Determined by Space Charge and Diffusion

The mathematical problem of one‐carrier space‐charge‐limited current (SCLC) step‐response in a perfect insulator is solved with a digital computer taking carrier diffusion into account. Curves of forward‐current density vs. time are presented with an error analysis and a brief discussion of the parameter influence for the case of a dielectric diode under different values of applied pulse voltages in the steady‐state current range where a square‐law behaviour begins to show up and inclusion of diffusion in the treatment is indispensable. The lowering of the voltage in this range deprives gradually the mean features of the SCLC transient ascertained for the diffusion‐neglected case. Last of all only the diffusion‐dominated current in the very beginning of the transients remains. The maximum time for observing the diffusion contribution to the pulse current estimated by Schilling and Schachter proves to be understated.