MEMS Gas Sensor Based on ZnCu-Based Oxide Semiconductors for H₂S Detection

In this work, a hydrogen sulfide (H<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub>S) MEMS sensor is designed by using the novel ZnCu-based oxide semiconductors derived from metal-organic frameworks. Different gas sensitization ways were established by heteroatom doping and heterogeneous interface construction. The results show the sensor based on CuO/ZnO semiconductors shows the unstable recovery behavior because of multiple interface formation after H<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub>S adsorption and reaction. However, the ZnCu-MOS-3 (Cu-doped ZnO) gas sensors demonstrate the great gas sensing performance for H<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub>S, featuring high response (16.19 for 20 ppm H<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub>S), fast response speed (33 s), and the ability to recover autonomously. In addition, a H<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub>S alarming platform is designed for preventing the human body from being poisoned. This work paves the way for the rational design of efficient gas sensors to monitor environmental H<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub>S concentrations.