Abstract
The conditions leading to the occurrence of the compensation rule in space-charge-limited current studies is discussed. It is shown that this effect is not fortuitous but that it can arise whenever a convergence point exists on current-voltage characteristics. Conditions leading to the appearance of a convergence point in such characteristics are discussed in terms of continuous and quasi-discrete trapping levels. The convergence point is shown to result when the concentration of a discrete (or nearly discrete) trap remains constant.