High performance humidity sensor based on crystalline copper tungstate nanoparticles at room temperature

This work demonstrates the synthesis and fabrication of Copper tungstate (CuWO4) nanoparticles-based humidity sensor. The as synthesized sample was characterized by X-ray diffraction, Raman spectroscopy, photoluminescence and high resolution transmission electron microscopy to study structural and morphological nature. The humidity sensing performance of CuWO4 nanoparticles based sensor device was tested at room temperature which was exposed to 11%-97% relative humidity levels. The sensitivity of the device was found to be similar to 767 at 97% relative humidity level. The CuWO4 nanoparticles sensing device showed ultra-low response and recovery time of similar to 39 sec and similar to 18 sec respectively. The high sensitivity and response/recovery was likely due to the high adsorption energy, fast charge transfer rate and low bonding energy of water molecules with CuWO4 nanoparticles. Our results indicate that CuWO4 nanoparticles-based humidity sensor device has great promising application as a portable device for control humidity detection.