Analysis of trap depths in anthracene by thermal and optical release of injected charge carriers

Abstract

Both thermally stimulated currents under high applied fields and photon-stimulated detrapping by monochromatic light under conditions of space charge limitation have been utilized to yield unequivocal estimates of the depths of separately identified electron and hole traps in single crystals of ultrahigh-purity anthracene. The traps are much more efficiently populated by appropriate injecting electrodes than by irradiation with light. Hole traps occur at 0.75, 0.85 and 0.95 eV above the valence band, and electron traps at 0.75 and 0.85 eV below the conduction band.