Hydrogen Fluoride Gas Sensor by Silicon Nanosheet Field-Effect Transistor

Chemical sensors are an essential part of modern society to ensure safety, from preventing pollution to saving lives. In particular, the demand for real-time monitoring of hydrogen fluoride (HF) increases continuously due to its high toxicity, contrary to its wide use in industries. In addition, compact size and low cost are favorable to utilize the sensor in wide spreading applications in industries. Here, we present a compact HF gas sensor with high sensitivity and selectivity. The HF sensors, fabricated in the form of field-effect transistors (FETs) using a cost-effective and mass-production friendly conventional semiconductor process, are shown to possess good electrical characteristics enabled by a silicon nanosheet (SiNS) current channel. High sensitivity on gas phase HF is achieved by the unique catalytic sensing membrane-platinum/polycrystalline lanthanum fluoride (Pt/poly-LaF3). The high responsivity (S-R) of 3071% at 25 ppm and the low limit of detection (LOD) of 219 ppb were achieved at room temperature (RT), along with a quick response time of 5.56 min, which are crucial for the workplace environmental safety. The developed HF sensor can be a potential candidate for the industrial mobile sensor platform.

Automated summary

Chemical sensors play a vital role in ensuring safety in modern society, from preventing pollution to saving lives. The demand for real-time monitoring of hydrogen fluoride (HF) is increasing due to its high toxicity and widespread use in industries. This study presents a compact HF gas sensor that exhibits high sensitivity and selectivity, utilizing field-effect transistors (FETs) fabricated through a cost-effective and mass-production friendly conventional semiconductor process. The sensor achieves high responsivity and low limit of detection at room temperature, making it a potential candidate for industrial mobile sensor platforms.