High-Performance Thin-Film Transistors with ZnO:H/ZnO Double Active Layers Fabricated at Room Temperature
Daoqin Wang,
Zongjin Jiang,
Linhan Li,
Deliang Zhu,
Chunfeng Wang,
Shun Han,
Ming Fang,
Xinke Liu,
Wenjun Liu,
Peijiang Cao,
Youming Lu
Affiliations
Daoqin Wang
Shenzhen Key Laboratory of Special Functional Materials, Guangdong Research Centre for Interfacial Engineering of Functional Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen 518000, China
Zongjin Jiang
Shenzhen Key Laboratory of Special Functional Materials, Guangdong Research Centre for Interfacial Engineering of Functional Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen 518000, China
Linhan Li
Shenzhen Key Laboratory of Special Functional Materials, Guangdong Research Centre for Interfacial Engineering of Functional Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen 518000, China
Deliang Zhu
Shenzhen Key Laboratory of Special Functional Materials, Guangdong Research Centre for Interfacial Engineering of Functional Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen 518000, China
Chunfeng Wang
Shenzhen Key Laboratory of Special Functional Materials, Guangdong Research Centre for Interfacial Engineering of Functional Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen 518000, China
Shun Han
Shenzhen Key Laboratory of Special Functional Materials, Guangdong Research Centre for Interfacial Engineering of Functional Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen 518000, China
Ming Fang
Shenzhen Key Laboratory of Special Functional Materials, Guangdong Research Centre for Interfacial Engineering of Functional Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen 518000, China
Xinke Liu
Shenzhen Key Laboratory of Special Functional Materials, Guangdong Research Centre for Interfacial Engineering of Functional Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen 518000, China
Wenjun Liu
Shenzhen Key Laboratory of Special Functional Materials, Guangdong Research Centre for Interfacial Engineering of Functional Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen 518000, China
Peijiang Cao
Shenzhen Key Laboratory of Special Functional Materials, Guangdong Research Centre for Interfacial Engineering of Functional Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen 518000, China
Youming Lu
Shenzhen Key Laboratory of Special Functional Materials, Guangdong Research Centre for Interfacial Engineering of Functional Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen 518000, China
H doping can enhance the performance of ZnO thin-film transistors (TFTs) to a certain extent, and the design of double active layers is an effective way to further improve a device’s performance. However, there are few studies on the combination of these two strategies. We fabricated TFTs with ZnO:H (4 nm)/ZnO (20 nm) double active layers by magnetron sputtering at room temperature, and studied the effect of the hydrogen flow ratio on the devices’ performance. ZnO:H/ZnO-TFT has the best overall performance when H2/(Ar + H2) = 0.13% with a mobility of 12.10 cm2/Vs, an on/off current ratio of 2.32 × 107, a subthreshold swing of 0.67 V/Dec, and a threshold voltage of 1.68 V, which is significantly better than the performance of single active layer ZnO:H-TFTs. This exhibits that the transport mechanism of carriers in double active layer devices is more complicated. On one hand, increasing the hydrogen flow ratio can more effectively suppress the oxygen-related defect states, thus reducing the carrier scattering and increasing the carrier concentration. On the other hand, the energy band analysis shows that electrons accumulate at the interface of the ZnO layer close to the ZnO:H layer, providing an additional path for carrier transport. Our research exhibits that the combination of a simple hydrogen doping process and double active layer construction can achieve the fabrication of high-performance ZnO-based TFTs, and that the whole room temperature process also provides important reference value for the subsequent development of flexible devices.
