Quantification of temperature rise in unipolar organic conductors during short voltage-pulse excitation using electrical testing methods

To quantify the rise in device temperature caused by Joule heating during short voltage-pulse excitation at high current densities (>10 A/cm²), the device temperatures of unipolar organic conductors were measured using electrical testing methods. For a maximum voltage amplitude of 59 V at a current density of ∼300 A/cm², temperature rose over 145°C within a pulse duration of 5 μs in an N,N'-di(1-naphthyl)-N,N'-diphenylbenzidine (α-NPD)-based single-carrier organic conductor. This result is in reasonable agreement with numerically calculated values. These findings indicate that suppressing the effects of Joule heating by carefully adjusting pulse width, substrate and organic materials, and device configuration is important to achieve further carrier injection in the ultra-high current density region (>1 kA/cm²).