Voltage Dependence of Unipolar Excess Bulk Charge Density in Organic Insulators
The steady flow of a unipolar current through a real insulator containing bulk trapping sites and provided with an injecting contact has been divided into several regimes(1). At low voltage, there should be an ohmic regime in which bulk, thermal generation of carriers predominates. This is followed at higher voltages by a space charge limited current (SCLC) regime, during which traps are filled by the excess, injected carriers. With certain trap distributions, it is sometimes found that at a particular voltage (VTFL) the current rises much more steeply with voltage than was the case for voltages less than VTFL. This voltage is referred to as the traps filled limit (TFL) voltage and it provides a ready measure of the total trap density in the crystal. At sufficiently high voltages, the contact becomes depleted and the current tends toward saturation.
KeywordsVoltage Dependence Image Force Delay Fluorescence Triplet Exciton Trap Carrier
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- (1).M.A. Lampert and P. Mark, Current Injection in Solids, Academic Press, New York, 1970.Google Scholar
- (6).M. Pope and H.P. Kallmann, Israel Journ. Chem. 10, 269 (1972).Google Scholar
- (7).A.I. Rozenthal and L.G. Paritskii, Sov. Phys. Semicond., 5, 2100 (1972).Google Scholar
- (10).M. Pope and W. Weston, Mol. Cryst. and Liq. Cryst. (to be published).Google Scholar
- (12).J.S. Bonham and L.E. Lyons, Aust. J. Chemo, 26, 489 (1973).Google Scholar
- (14).N.E. Geacintov and M. Pope in Proc. 3rd Int. Photocond. Conf. Stanford 1969, ed. by Pell, Pergamon Press Ltd. 1970.Google Scholar