Department of Physics, Indian Institute of Technology Jodhpur, Jodhpur-342011 India.
Nanotechnology. 2019 May 31;30(22):224001. doi: 10.1088/1361-6528/ab0321. Epub 2019 Jan 30.
Here, we demonstrate improved NO gas sensing properties based on reduced graphene oxide (rGO) decorated VO thin film. Excluding the DC sputtering grown VO thin film, rGO was spread over VO thin film by the drop cast method. The formation of several p-n heterojunctions was greatly affected by the current-voltage relation of the rGO-decorated VO thin film due to the p-type and n-type nature of rGO and VO, respectively. Initially with rGO decoration on VO thin film, current decreased in comparison to the pristine VO thin film, whereas depositing rGO film on a glass substrate drastically increased current. Among all sensors, only the rGO-decorated VO sensor revealed a maximum NO gas sensing response for 100 ppm at 150 °C, and it achieved an approximately 61% higher response than the VO sensor. The elaborate mechanism for an extremely high sensing response is attributed to the formation and modulation of p-n heterojunctions at the interface of rGO and VO. In addition, the presence of active sites like oxygenous functional groups on the rGO surface enhanced the sensing response. On that account, sensors based on rGO-decorated VO thin film are highly suitable for the purpose of NO gas sensing. They enable the timely detection of the gas, further protecting the ecosystem from its harmful effects.
在这里，我们展示了基于还原氧化石墨烯 (rGO) 修饰 VO 薄膜的改进的 NO 气体传感性能。除了直流溅射生长的 VO 薄膜外，rGO 还通过滴铸法覆盖在 VO 薄膜上。由于 rGO 和 VO 分别具有 p 型和 n 型性质，因此 rGO 修饰的 VO 薄膜的电流-电压关系极大地影响了多个 p-n 异质结的形成。最初，与原始的 VO 薄膜相比，在 VO 薄膜上进行 rGO 修饰会导致电流减小，而在玻璃基板上沉积 rGO 薄膜会大幅增加电流。在所有传感器中，只有 rGO 修饰的 VO 传感器在 150°C 时对 100ppm 的 NO 气体显示出最大的气体传感响应，其响应比 VO 传感器高约 61%。极高的传感响应的精细机制归因于 rGO 和 VO 界面处形成和调制 p-n 异质结。此外，rGO 表面上含氧官能团等活性位点的存在增强了传感响应。因此，基于 rGO 修饰的 VO 薄膜的传感器非常适合用于 NO 气体传感。它们能够及时检测气体，从而进一步保护生态系统免受其有害影响。
