Abstract
A method is proposed for the measurement of space‐charge‐limited current characteristics in high‐resistivity materials which overcomes the difficulty of ensuring thermal equilibrium conditions throughout the measurements. Measurements carried out on high‐resistivity single crystals of CdS, using this method, show the well‐known characteristics of space‐charge‐limited current. It is shown that if proper care is not taken to ensure thermal equilibrium, the measured I‐V characteristics depend strongly on the history of the sample and their interpretation on the basis of space‐charge‐limited current theories is unjustified and meaningless.