Abstract
A new type of nitrogen dioxide (NO2) gas sensor based on copper phthalocyanine (CuPc) thin film transistors (TFTs) with a simple, low-cost UV–ozone (UVO)-treated polymeric gate dielectric is reported here. The NO2 sensitivity of these TFTs with the dielectric surface UVO treatment is ≈400× greater for [NO2] = 30 ppm than for those without UVO treatment. Importantly, the sensitivity is ≈50× greater for [NO2] = 1 ppm with the UVO-treated TFTs, and a limit of detection of ≈400 ppb is achieved with this sensing platform. The morphology, microstructure, and chemical composition of the gate dielectric and CuPc films are analyzed by atomic force microscopy, grazing incident X-ray diffraction, X-ray photoelectron spectroscopy, and Fourier transform infrared spectroscopy, revealing that the enhanced sensing performance originates from UVO-derived hydroxylated species on the dielectric surface and not from chemical reactions between NO2 and the dielectric/semiconductor components. This work demonstrates that dielectric/semiconductor interface engineering is essential for readily manufacturable high-performance TFT-based gas sensors.
Original language | English (US) |
---|---|
Article number | 1701706 |
Journal | Advanced Materials |
Volume | 29 |
Issue number | 31 |
DOIs | |
State | Published - Aug 18 2017 |
Keywords
- UV–ozone
- interface trap
- nitrogen dioxide sensors
- organic thin-film transistors
ASJC Scopus subject areas
- Materials Science(all)
- Mechanics of Materials
- Mechanical Engineering