Investigating the Flexibility of ZnO Nanorod Growth Parameters for Humidity Sensor Design

A study on the effect of ZnO nanorod growth conditions on humidity sensing is presented. Glass substrates were coated with triangular ZnO nanorods using a hydrothermal method, with growth durations of 5, 10, and 15 hours, and coating lengths in triangular shape varying from 1 mm to 13 mm. A commercial LED and photodiode were utilized in the measurement setup, functioning as the light source and photodetector, respectively, and interfaced with an Arduino for data processing. Humidity experiments were conducted in a controlled chamber using different combinations of these growth parameters. The results indicated that a combination of 10 hours growth time and 7 mm coating length produced a sensing response comparable to that of a 15-hour growth time and 4 mm coating length at 80% relative humidity. This demonstrates that optimal sensor performance can be achieved through various fabrication settings, suggesting that flexibility in process parameters allows for more efficient and cost-effective sensor design without sacrificing the sensor performance. By offering multiple viable fabrication paths, the process becomes more scalable and versatile, allowing for the design of sensor devices that maintain high sensitivity while optimizing manufacturing efficiency. This is crucial for improving the practicality of ZnO-based humidity sensors in commercial applications.