We report on p-channel depletion mode organic inverter composed of two pentacene thin-film transistors (TFTs), which have different channel thickness each other. Adopting thin hydrophilic AlOx as dielectric, the 25 nm-thin channel pentacene TFT showed lower threshold voltage (VTH) than that of 50 nm-thick channel-TFT, while on hydrophobic poly-4-vinyphenol (PVP) dielectric the results became opposite. We utilized the different VTH caused by different channel thickness to operate the inverter that consists of driver- and load-TFTs. The 50 nm-thick pentacene operated as the channel layer of driver-TFT on AlOx, but on PVP dielectric the 25 nm-thin pentacene layer played as the driver channel. Maximum voltage gain of ∼22 under -8 V supply voltage was achieved when the dielectric layer was optimized.
Bibliographical noteFunding Information:
Authors acknowledge the financial support from KOSEF (NRL program: Grant No. 2009-8-0403), from MKE (the fundamental R&D Program for Core Technology of Materials: No. 2008-8-1410, the IT R&D Program for Smart window with transparent electronic devices: No. 2008-8-0613), Information Display R&D center, one of the 21st Century Frontier R&D Program: No. F0004022-2009], and Brain Korea 21 program.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Materials Chemistry
- Electrical and Electronic Engineering