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

TL;DR

This paper investigates how charge transport in metal-organic diodes transitions from injection-limited to space-charge-limited current as temperature varies, highlighting the complex interplay between these mechanisms.

Contribution

It provides experimental evidence of a temperature-dependent transition between injection-limited and space-charge-limited currents in organic diodes, challenging simplified models.

Findings

Observed ILC-to-SCLC transition in Ag/pentacene/Ag diodes with temperature change

Demonstrated the complex interplay between injection and bulk conduction mechanisms

Highlighted the importance of considering both mechanisms in device modeling

Abstract

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