Carbon Monoxide Sensor Based on Printed ZnO

This work describes the fabrication of a Carbon monoxide (CO) sensor based on a Zinc oxide (ZnO) Schottky diode that can detect CO at low concentrations as low as one part per million (ppm) at room temperature. Different additive microfabrication techniques are used to fabricate the devices. A precisely controlled fabrication is enabled by employing a microcantilever (
$\mu \text{C}$
) printing system. The fully printed sensor has a high sensitivity of 23.7% towards CO at room temperature. The height of the Schottky barrier significantly influences the response of the device. Furthermore, all sensors specificity was analyzed for some of the gases, and volatile organic compounds (VOCs) found in breath. The fully printed device exhibited a negative temperature coefficient of resistivity for temperatures ranging from 50 to 300 Kelvin. This work aims to develop a proof-of-concept for enhancing room temperature sensing by developing a Schottky sensor.