Abstract
A novel method to design metal oxide thin-film transistor (TFT) devices with high performance and high photostability for next-generation flat-panel displays is reported. Here, we developed bilayer metal oxide TFTs, where the front channel consists of indium-zinc-oxide (IZO) and the back channel material on top of it is hafnium-indium-zinc-oxide (HIZO). Density-of-states (DOS)-based modeling and device simulation were performed in order to determine the optimum thickness ratio within the IZO/HIZO stack that results in the best balance between device performance and stability. As a result, respective values of 5 and 40 nm for the IZO and HIZO layers were determined. The TFT devices that were fabricated accordingly exhibited mobility values up to 48 cm 2/(V s), which is much elevated compared to pure HIZO TFTs (∼13 cm 2/(V s)) but comparable to pure IZO TFTs (∼59 cm 2/(V s)). Also, the stability of the bilayer device (-1.18 V) was significantly enhanced compared to the pure IZO device (-9.08 V). Our methodology based on the subgap DOS model and simulation provides an effective way to enhance the device stability while retaining a relatively high mobility, which makes the corresponding devices suitable for ultradefinition, large-area, and high-frame-rate display applications.
Original language | English |
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Pages (from-to) | 5416-5421 |
Number of pages | 6 |
Journal | ACS Applied Materials and Interfaces |
Volume | 4 |
Issue number | 10 |
DOIs | |
State | Published - 24 Oct 2012 |
Keywords
- density-of states
- hafnium-indium-zinc-oxide
- indium-zinc-oxide
- metal oxide thin-film transistors
- photostability