Field-effect transistor CO2 detector based on few layers of black phosphorus

Sensitive gas sensors are a key requirement for a large number of applications. Two-dimensional (2D) materials exhibit excellent properties for low power consumption sensing devices due to their ultra-high surface-to-volume ratios. In this work, we used 2D materials such as black phosphorus (BP) for developing a field-effect transistor (FET) gas sensor. We demonstrated C$\mathrm{O}_{2}-$sensing performance at room temperature. A clear shift in current was observed during switching on and off the CO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> flow. The ability to enhance the sensor response by modulating the gate voltage highlights the advantage of our FETs over resistor-based sensors. Our results show that the proposed method is a promising strategy to improve 2D materials CO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> detectors and has a potential for applications in advanced gas-sensing devices.