Investigation of the device instability feature caused by electron trapping in pentacene field effect transistors

摘要

The phenomenon of device instability governed by electron trapping was investigated in pentacene field-effect transistors. We found that the threshold voltage shift (△V_T) increases significantly when the device is exposed to photo-irradiation with the depletion gate bias. This effect reveals that a number of electron trapping sites are located in the pentacene band gap, presenting the mechanism of the photo-induced △V_T. In addition, we found the specific shift of bias-stressed △V_T under a monochromatic of 690-500 nm, which reflects that the electron trap states would be distributed between the energy levels of 1.8 and 2.5 eV in the gap state.