Yang Xiang, Jiang Shu, Li Jun, Zhang Jian-Hua, Li Xi-Feng
Key Laboratory of Advanced Display and System Applications of Ministry of Education, Shanghai University Shanghai 200072 China.
College of Materials Science and Engineering, Shanghai University Shanghai 200072 China.
RSC Adv. 2018 Jun 7;8(37):20990-20995. doi: 10.1039/c8ra02925c. eCollection 2018 Jun 5.
In this paper, W-doped ZnSnO (WZTO) thin films and TFT devices are successfully fabricated by a wet-solution technique. The impact of W doping on the film structure, surface morphology, optical properties and chemical compositions of ZTO thin films is analyzed by atomic force microscopy, X-ray diffraction, UV-visible spectroscopy and X-ray photoelectron spectroscopy. The results show that the WZTO thin films have a smooth surface, amorphous structure and fewer oxygen vacancies with increasing W levels. The oxygen vacancy concentration of WZTO thin films is reduced from 40% to 27% with W incorporation. Compared with films free of W doping, for example ZnSnO TFTs, the positive bias stress stability of WZTO TFTs and long-term stability in air are improved obviously and the shift of the threshold voltage ( ) is restrained about six times. The critical reason for the improvement of the ZTO TFT properties is attributed to W-doping, wherein the suppression of oxygen vacancies by W ions plays a dominant role in changing the performance of ZTO thin films and the stability of TFTs.
在本文中，通过湿溶液技术成功制备了W掺杂的ZnSnO（WZTO）薄膜和TFT器件。采用原子力显微镜、X射线衍射、紫外可见光谱和X射线光电子能谱分析了W掺杂对ZTO薄膜的结构、表面形貌、光学性质和化学成分的影响。结果表明，随着W含量的增加，WZTO薄膜表面光滑，呈非晶结构，氧空位减少。随着W的掺入，WZTO薄膜的氧空位浓度从40%降低到27%。与未掺杂W的薄膜（如ZnSnO TFT）相比，WZTO TFT的正偏压应力稳定性和在空气中的长期稳定性明显提高，阈值电压（ ）的漂移受到约六倍的抑制。ZTO TFT性能改善的关键原因归因于W掺杂，其中W离子对氧空位的抑制在改变ZTO薄膜性能和TFT稳定性方面起主导作用。
