Bias-Dependent Generation and Quenching of Defects in Pentacene

TL;DR

This study investigates a bias-induced defect in pentacene crystals that affects charge transport, highlighting its creation, decay, and dependence on bias stress, illumination, and atomic motion.

Contribution

It reveals a bias-dependent defect mechanism in pentacene with specific activation energy and metastable effects, advancing understanding of defect dynamics in organic semiconductors.

Findings

Defect persists for an hour at room temperature in dark conditions.

Defect decays within seconds under 420nm illumination.

Hole trap characterized at Ev + 0.38eV with 0.67eV activation energy.

Abstract

We describe a defect in pentacene single crystals that is created by bias stress and persists at room temperature for an hour in the dark but only seconds with 420nm illumination. The defect gives rise to a hole trap at Ev + 0.38eV and causes metastable transport effects at room temperature. Creation and decay rates of the hole trap have a 0.67eV activation energy with a small (108 s-1) prefactor, suggesting that atomic motion plays a key role in the generation and quenching process.