Temperature-dependent transition from injection-limited to space-charge-limited current in metal-organic diodes

摘要

Based on the assumption that the contact barrier height determines thecurrent flow in organic semiconductor-based electronic devices, chargeinjection at metal-organic (MO) interfaces has been extensively investigated,while space-charge conduction in organic bulk is generally overlooked. Recenttheoretical modeling and simulation have pointed out that such a simplificationis questionable due to the hopping nature of charge injection andhopping-related space-charge conduction. Here we show experimentally thatcharge transport in metal-organic diodes is complex interplay betweeninjection-limited current (ILC) and space-charge-limited current (SCLC). Wereport the experimental observation of ILC-to-SCLC transition inAg/pentacene/Ag diodes as a function of temperature.