Hot-Carriers’ Effect on the Performance of Organic Schottky Diodes

Abstract

Because thermionic emission or tunneling occurs when carriers overcome or tunneling through the barrier for any Schottky diode, hot carriers caused by the applied electric field can enhance carrier thermionic emission or carrier tunneling. An analytical and physical organic diode current equation that includes hot-carriers effect on the diode current equation has been proposed. When organic diode current equation has the same mathematical expression as Shockley diode current equation does, hot-carrier effects in organic semiconductor diodes can be a physical origin of the ideality factor and can reduce the barrier height for both band-like conduction mechanism and hopping conduction mechanism. The voltage-dependent ideality factor and temperature-dependent ideality factor predicted by the proposed model agree well with experimental data of organic semiconductor diodes reported in the literature. The proposed model can also physically explain the experimental relation between the ideality factor and the effective barrier height. The proposed model is useful in better physically understanding the carrier transport in organic semiconductor diodes. It also benefits to better optimize the organic semiconductor diode performance by tuning material properties.

Keywords

• Organic Schottky diode
• organic semiconductor
• Schottky barrier
• thermionic emission