The authors report on the origin of channel/dielectric interfacial states modified by ultraviolet (UV) irradiation on pentacene thin-film transistors (TFTs) with poly-4-vinylphenol and AlOxdouble gate dielectric. Exposing the device to 352 nm UV irradiation on caused a positive threshold voltage (Vth) shift, and then photo-excited charge-collection spectroscopy (PECCS) was applied to the device to clarify the changes of the interfacial density of states (DOS) as the origin of Vthmodification. From the PECCS measurement, it could be probed that there was a drastic decrease in DOS for deep traps at ∼ 1.31 and ∼1.38 eV above the highest occupied molecular orbital level of pentacene. Consequently, we can conclude that the positive shift of Vthfor pentacene-TFT by UV irradiation results from the elimination of deep hole traps, which could be introduced by the interfacial dipoles at the channel/dielectric interface.
|Number of pages||4|
|Journal||Physica Status Solidi (A) Applications and Materials Science|
|Publication status||Published - 2014 Dec|
Bibliographical notePublisher Copyright:
© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Surfaces and Interfaces
- Surfaces, Coatings and Films
- Electrical and Electronic Engineering
- Materials Chemistry