Abstract
We report on the surface-induced time-dependent instability of ZnO based thin-film transistors (ZnO-TFTs) with interdigitated source/drain (S/D) electrodes. As time elapsed, a considerable shift of threshold voltage (VT) was observed (by ~ - 16 V) from our TFT. Contact angle of de-ionized water on ZnO surface also changed from 30° to 110°, revealing time-dependent surface state change. According to X-ray photoemission spectroscopy (XPS) measurements, the Zn 2p3/2 core-level peak and the valence band maximum (VBM) of aged ZnO surface shifted to the higher binding energy by 0.3 eV, which implies a downward energy band bending of the ZnO back channel-surface. We conclude that without passivation layer any bottom gate ZnO-TFT meets the surface-induced electrical instabilities due to the time-dependent conductance of ZnO surface.
Original language | English |
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Pages (from-to) | 6345-6348 |
Number of pages | 4 |
Journal | Thin Solid Films |
Volume | 517 |
Issue number | 23 |
DOIs | |
Publication status | Published - 2009 Oct 1 |
Bibliographical note
Funding Information:This work was supported by the fundamental R&D Program for Core Technology of Materials funded by the Ministry of Commerce, Industry and Energy, KOSEF (R01-2006-000-11277-0), the IT R&D program of MKE/IITA [2006-S079-02, Smart window with transparent electronic devices], and Brain Korea 21 Program.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Surfaces and Interfaces
- Surfaces, Coatings and Films
- Metals and Alloys
- Materials Chemistry