将化学刻蚀法与金属辅助刻蚀法相结合，制备了形貌统一、分布均匀的高质量柔性硅纳米线阵列结构，用石墨烯量子点对其表面进行修饰，得到了表面稳定且具有强载流子传输能力的柔性石墨烯量子点/硅纳米线核?壳结构阵列，用其制备气敏设备检测NO2. 结果表明，基于该阵列的电阻式气敏设备对NO2的检测灵敏性及可重复性极高，检测浓度极限达20 mg/m3；不同弯曲度的柔性石墨烯量子点/硅纳米线阵列的气敏特性未大幅度降低，弯曲90o时响应电流峰值为未弯曲时的70%.
The detection of toxic and harmful gas NO2 is an important measure to reduce environmental pollution. In the field of gas detection, silicon nanowires array is an excellent material because of its high specific surface area, high surface activity, surface functionalized modification and admirable biocompatibility. Therefore, silicon nanowires array has attracted a wide range of attention in the field of gas detection. Graphene quantum dots exhibit excellent optical, electrical, quantum confinement effects and other unique properties. It is widely used in photovoltaic devices, electronic devices, biosensors and other fields. The nano size of graphene quantum dots makes it possess great biocompatibility and chemical stability, furthermore, its aqueous solution can functionalized modify different types and sizes substances. The chemical etching method was combined with the metal assisted etching method, based on P monocrystalline silicon, to prepare high-quality flexible silicon nanowires array with uniform morphology. A flexible graphene quantum dots/silicon nanowires core?shell structure array with stable surface and strong carrier transport ability was obtained through the further modification with graphene quantum dots on its surface, the array was used to detecting NO2. The results showed that, by the modification of graphene quantum dots, the surface oxidation of silicon nanowires array can be avoided and the surface stability of silicon nanowires array is improved. What’s more, owing to the strong ability of graphene quantum dots to attract and store the electrons, the carrier migration rate of the device is further improved. When the device is used for gas detection, resistive gas sensor based on this array had extremely high sensitivity and repeatability of NO2, and the detection limit of NO2 reached to 20 mg/m3. The gas sensing properties of the flexible graphene quantum dots/silicon nanowires array could be maintained with different bending angles. The response current peak when the bending angle was 90o can still hold as 70% of the value before bending.
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