In recent years, the demands for high-performance gas sensors are rapidly increasing in many fields including environmental monitoring, public health and security, medical diagnostics, and industrial process monitoring. Among various types of gas sensors, the resistive metal-oxide-semiconductors (MOS) are very attractive and widely applied due to their high sensitivity, low cost, facile operation, and high compatibility with microfabrication processes. The working principle of such gas sensors is based on the reversible changes in the sensor’s resistance caused by the gas adsorption and reaction on the surface of the sensing materials. Thus, the primary consideration for the fabrication of MOS gas sensors is the design and optimization of the sensing materials toward different target gases. Furthermore, the development of nanoscience and nanotechnology provides additional opportunities for controllable syntheses of high-performance MOS gas sensing materials. As confirmed by many reports, reducing the physical size of the building units of the sensing materials is an effective strategy to enhance the gas sensing properties of resistive MOS sensors. Specifically, a dramatic increase in sensor response can be achieved when the grain size becomes comparable or smaller than the Debye Screening Length (LD). Quantum dots (QDs), being one of the zero-dimensional nanomaterials with sizes below 10 nm, have attracted significant interest due to their uniquely tunable size-dependent electronic, chemical, and optical properties, leading to entirely new avenues for many applications. In this project, we aim to synthesize MOS QDs with control over the physical size and chemical compositions and explore their applications in high-performance gas sensing.
Project ended: 01/21/2021