Effects of discrete trap levels on organic light emitting diodes

Abstract

We have studied the effects of discrete trap levels on organic light emitting diodes under the space charge limited conditions. The interplay among the free, discrete, and exponential trap charges in single- and double-carrier devices is discussed. The sharp transitions in the current-voltage characteristics often associated with the discrete trap levels in single-carrier devices may disappear in double-carrier devices such as the organic light emitting diodes. The physics is elucidated using the energy and charge profiles. © 1999 American Institute of Physics.