Steady‐State and Transient Currents in Organic Liquids by Injection from a Tunnel Cathode

Experimental data are presented on the currents induced in organic liquids by injection from a tunnel cathode. The injection level was varied over a wide range resulting in almost no space‐charge limitation to almost complete space‐charge limitation. Results were different from that usually observed in solids, in that at low fields, the steady‐state current was proportional to V², while at high fields the current was proportional to V. By proper choice of electrode spacing and applied voltage, space‐charge‐limited current transients as low as 10⁻¹¹ A/cm² and 5 sec transit times were observed. A smooth transition between the electrode‐limited and the space‐charge limited regimes was achieved by varying the junction voltage that varied the injection level.