On charge-carrier trapping in insulating solids as investigated by the space-charge-limited current (SCLC) technique: a cautionary note

From the results of measurements employing the SCLC technique, a trapping level of depth approximately 0.7 eV below the transport band is apparently common to several insulating solids. This is considered to be the result of a mathematical relation inherent in the equation used for the derivation of trapping parameters, rather than the presence of the same chemical or structural entity acting as a trapping centre.