Adamu Bala Ismail, Falak Attia, Tian Yi, Tan Xinghua, Meng Xiangmin, Chen Peipei, Wang Hanfu, Chu Weiguo
Nanofabrication Laboratory, CAS Center for Excellence in Nanoscience , National Center for Nanoscience and Technology , Beijing 100190 , China.
Center of Materials Science and Optoelectronics Engineering , University of Chinese Academy of Sciences , Beijing 100039 , China.
ACS Appl Mater Interfaces. 2020 Feb 19;12(7):8411-8421. doi: 10.1021/acsami.9b19971. Epub 2020 Feb 5.
High sensitivity, low limit of detection (LOD), and short response and recovery times at room temperature (RT) are critical for gas sensors. For NO, different binary metal oxide-based sensors were developed to achieve superior performance at elevated temperatures instead of RT. Herein, we report on CuO@CuO and CuMoO@CuO sensors with CuO and CuMoO micro/nanorods vertically aligned on the CuO layers, which were directly fabricated using a facile, low-cost, and catalyst-free chemical vapor deposition (CVD) technique. Their sensing performance tests revealed that the CuMoO@CuO p-p heterojunction sensors exhibited a high response of 160% to 5 ppm NO, an excellent sensitivity of 50% ppm, a low LOD of 2.30 ppb, a short response time of 49 s, and a rapid recovery of 241 s at RT, obviously better than those for CuO@CuO sensors. The superior performance of CuMoO@CuO sensors could be attributed to the Schottky heterojunction formed between -CuMoO micro/nanorods and -CuO films, the catalytic effect, and the anisotropic nature of CuMoO micro/nanorods. This study not only provides a simple, low-cost, and batchable fabrication method of homo/heterojunction sensors with micro/nanorods vertically aligned on films but also opens an avenue for sensor design by tuning the Schottky barrier height to enhance RT performance.
高灵敏度、低检测限（LOD）以及在室温（RT）下短的响应和恢复时间对于气体传感器至关重要。对于NO，已开发出不同的基于二元金属氧化物的传感器，以在高温而非室温下实现卓越性能。在此，我们报道了CuO@CuO和CuMoO@CuO传感器，其中CuO和CuMoO微/纳米棒垂直排列在CuO层上，它们是使用简便、低成本且无催化剂的化学气相沉积（CVD）技术直接制备的。它们的传感性能测试表明，CuMoO@CuO p-p异质结传感器在室温下对5 ppm NO表现出160%的高响应、50% ppm的优异灵敏度、2.30 ppb的低检测限、49 s的短响应时间以及241 s的快速恢复，明显优于CuO@CuO传感器。CuMoO@CuO传感器的优异性能可归因于-CuMoO微/纳米棒与-CuO薄膜之间形成的肖特基异质结、催化作用以及CuMoO微/纳米棒的各向异性。本研究不仅提供了一种简单、低成本且可批量制备的在薄膜上垂直排列微/纳米棒的同质/异质结传感器的制造方法，还通过调节肖特基势垒高度来提高室温性能为传感器设计开辟了一条途径。
