Electron traps and hysteresis in pentacene-based organic thin-film transistors

In the absence of charge storage or slow polarization in the gate dielectric, the hysteresis in the current-voltage (I-V) characteristics of pentacene-based organic thin-film transistors (OTFTs) is dominated by trapped electrons in the semiconductor. The immobile previously stored negative charge requires extra holes to balance it, resulting in the early establishment of the channel and extra drain current. Inferred from I-V characteristics, this simple electrostatic model qualitatively explains memory effects in pentacene-based OTFTs, and was verified by a time domain measurement.