Hydrothermally Grown ZnO Nanorod-Based Ag–ZnO–Ag UV Sensors on Glass Substrates

Background: ZnO nanorod arrays (ZnO-NRA) are promising materials for the current research. The hydrothermal synthesis is considered as the most promising method for ZnO growth. ZnO-NRA-based UV sensors have been focused upon because of their use in the various fields. In this work, we fabricated zinc oxide (ZnO) nanorod array (NRA)-based metal–semiconductor–metal (MSM) UV sensors on glass substrates. Methods: The ZnO-NRA was grown above ZnO-seed layer/glass using a low-temperature hydrothermal method. The MSM structure-based sensor was fabricated by depositing interdigitated contacts of Ag on NRA/glass samples. The crystalline structure and surface morphology of NRA were examined by X-ray diffraction and scanning electron microscopy. The values of responsivity and photocurrent to dark current ratio were obtained from the I-V characteristics of the MSM UV sensors. Results: The grown single-crystalline ZnO nanorods were highly dense and uniform. The contrast ratio (C.R.) was found to be 9.20 at 1.50 V. The responsivity of UV sensors was found to be 0.122 mA/W at λ=365 nm. Conclusion: ZnO nanorods were grown on glass substrates using a low-temperature hydrothermal method and the I-V characteristics of Ag/ZnO-NRA/Ag based MSM UV sensors were tested under UV light. The MSM UV sensors exhibited a photo current to dark current ratio of ~ 9.20 at 1.50 V, and a responsivity of 0.122 mA/W at 365 nm. These results can provide a deep insight into fabricating simpler, efficient, and inexpensive UV sensors for practical applications.