Lin Hwai-En, Katayanagi Yuta, Kishi Tetsuo, Yano Tetsuji, Matsushita Nobuhiro
Department of Materials Science and Engineering, School of Materials and Chemical Technology, Tokyo Institute of Technology 2-12-1 Ookayama Meguro-ku Tokyo 152-8550 Japan
Department of Technology Education, Faculty of Education, Gunma University 4-2 Aramaki-machi Maebashi Gunma 371-8510 Japan.
RSC Adv. 2018 Aug 28;8(53):30310-30319. doi: 10.1039/c8ra04355h. eCollection 2018 Aug 24.
An all-solution-processed transparent tin oxide (SnO)-based humidity sensor was directly prepared on borosilicate glass (SnO-G) and a flexible polyethylene terephthalate (SnO-PET) substrate without using a template. The entire process included film deposition by a spin-spray process at 90 °C and subsequent hot water treatment (HWT) at 100 °C. The resistivity of the films dramatically decreased and had semiconductor characteristics after the HWT, even though the as-prepared SnO-G and SnO-PET samples were insulators. Based on the results, the variation of the resistivity could be attributed to the formation of a hydroxyl layer on the crystallized SnO surface. With the help of the HWT on the SnO films, the formation of tin hydroxyl derivatives provided mobile protons, which led to the variation of the electrical properties of SnO at ambient conditions with different humidities. The sensitivity of the SnO-G-HWT and SnO-PET-HWT at 95% relative humidity (RH) was 35.2 and 3.5 times higher, respectively, than that at 5% RH. Both the sensitivity of the SnO-G-HWT and SnO-PET-HWT samples showed a good uptrend corresponding to the increase of RH at 20 ± 1 °C, and the response/recovery time of SnO-G-HWT and SnO-PET-HWT was 51/38 s and 69/47 s in the % RH range of 30-70% at 20 ± 1 °C, respectively.
一种全溶液处理的透明氧化锡（SnO）基湿度传感器在硼硅酸盐玻璃（SnO-G）和柔性聚对苯二甲酸乙二酯（SnO-PET）基板上直接制备而成，无需使用模板。整个过程包括在90℃下通过旋喷工艺进行薄膜沉积以及随后在100℃下进行热水处理（HWT）。尽管制备的SnO-G和SnO-PET样品是绝缘体，但经过HWT后，薄膜的电阻率显著降低并具有半导体特性。基于这些结果，电阻率的变化可归因于在结晶的SnO表面形成了羟基层。借助于对SnO薄膜的HWT，锡羟基衍生物的形成提供了可移动的质子，这导致了SnO在不同湿度的环境条件下电学性能的变化。SnO-G-HWT和SnO-PET-HWT在相对湿度（RH）为95%时的灵敏度分别比在5%RH时高35.2倍和3.5倍。在20±1℃时，SnO-G-HWT和SnO-PET-HWT样品的灵敏度均随RH的增加呈现出良好的上升趋势，并且在20±1℃、RH范围为30-70%时，SnO-G-HWT和SnO-PET-HWT的响应/恢复时间分别为51/38秒和69/47秒。
