Carrier traps in ultra-high purity single crystals of anthracene

摘要: Measurements of space-charge-limited currents, arising from electron-injection or hole-injection suitable ohmic contacts, have been carried out at room temperature, on a variety anthracene crystals differing only in the nature gas (He, Xe, N2 vacuum) exposed to melt which grew. The principal aim work is characterize energetics carrier traps present samples not deliberately deformed. It shown that Gaussian distribution trapping states, as well more generally used exponential one, can readily account for observed current, voltage dependences. Correlations found between calculated total trap density, H, and characteristic energy kTc grown under different atmospheres. These parameters, EL, h(EL), refer, respectively, depth density deepest traps, serve define properties are essentially same (both with respect their EL∼0.7 eV) electrons holes. This fact suggests origin may be ascribed structural imperfections, are, turn, associated crystallographic perturbations brought about by presence inert species.It also explanations compensation law electrical conductivity based continuous distributions need universal applicability, and, particular, invalid anthracene.