Sui Yanxin, Liang Huili, Chen Quansheng, Huo Wenxing, Du Xiaolong, Mei Zengxia
Key Laboratory for Renewable Energy, Beijing Key Laboratory for New Energy Materials and Devices, Beijing National Laboratory for Condensed Matter Physics , Institute of Physics, Chinese Academy of Sciences , Beijing 100190 , P. R. China.
School of Physical Sciences , University of Chinese Academy of Sciences , Beijing 100049 , China.
ACS Appl Mater Interfaces. 2020 Feb 19;12(7):8929-8934. doi: 10.1021/acsami.9b22400. Epub 2020 Feb 6.
In present work, we report a room-temperature ozone sensor using InGaZnO (IGZO)-decorated amorphous GaO (a-GaO) thin films. The gas sensing tests demonstrate that the topmost IGZO modification can significantly promote the sensors' responsivity. Intriguingly, the sensing capability presents a first increasing and then decreasing tendency as the surface morphology of IGZO develops from dispersed particles to a continuous film. Finite difference time domain (FDTD) simulation results prove that IGZO nanoparticles can remarkably increase the surface density of photogenerated electrons, clearly manifesting a strong dependence on IGZO particle size and contributing to the boosted responsiveness. However, once IGZO particles coalesce into a thin film, the ozone sensor's responsivity starts to decrease even though the number of photogenerated carriers still increases. The smaller specific surface area of IGZO thin film is believed to be responsible for this phenomenon. The proposed ozone gas sensors own the merits of low cost, room-temperature detection, easy integration, and mass production, significantly expanding the application fields of a-GaO thin film.
在本工作中，我们报道了一种使用InGaZnO（IGZO）修饰的非晶GaO（a-GaO）薄膜的室温臭氧传感器。气敏测试表明，最顶层的IGZO修饰可以显著提高传感器的响应度。有趣的是，随着IGZO的表面形态从分散颗粒发展为连续薄膜，传感能力呈现出先增加后降低的趋势。时域有限差分（FDTD）模拟结果证明，IGZO纳米颗粒可以显著提高光生电子的表面密度，清楚地表明对IGZO粒径有很强的依赖性，并有助于提高响应度。然而，一旦IGZO颗粒聚结成薄膜，即使光生载流子的数量仍然增加，臭氧传感器的响应度也开始降低。据信，IGZO薄膜较小的比表面积是造成这种现象的原因。所提出的臭氧气体传感器具有低成本、室温检测、易于集成和大规模生产的优点，显著扩展了a-GaO薄膜的应用领域。
