Enhancement of Humidity Sensitivity by Adjusting Aspect Ratio of PVP-Modified Hexagonal ZnO Nanorods

초록

Humidity sensors with high sensitivity, rapid response and facile fabrication process have received considerable attention in recent years. Herein, we report a facile fabrication process of PVP modified ZnO nanorod sensors (PVP-ZnO) with low (PVP-ZnO-1) and high aspect ratios length to diameter (PVP-ZnO-2) by depositing the sensing layer on an interdigitated Electrodes (IDE) on a PET substrate. The PVP-ZnO-2 shows a significantly higher capacitive humidity sensitivity of ~ 99,397% at 85% relative humidity (RH) compared to the PVP-ZnO-1 sensor (41,647%). PVP-ZnO-2 sensor also showed rapid response and recovery times 7s and 10s under cyclic humidity conditions. Benefiting from the high humidity sensitivity performance, of PVP-ZnO-2, changes in capacitance during different breathing levels and Morse code messaging have been demonstrated. This developed sensor would provide the immense potential of high-surface-area nanomaterial-based humidity sensors for next-generation environmental monitoring and biomedical applications.

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