In this letter, the influence of drain bias on the threshold voltage instability in pentacene-based organic thin-film transistors (OTFTs) was studied. By applying different drain biases to adjust the channel carrier concentration in linear mode, the threshold voltage shift was found to be proportional to the carrier concentration. The experimental data can be well quantitatively explained by the drain bias-stress theory developed for a-Si TFTs. The outcome gives the insight of the degradation mechanism of OTFTs and is important for the design of OTFT pixel circuit, OTFT analog amplifiers, or OTFT active loads.
- Bias-stress effect
- Organic thin-film transistor (OTFT)