Optimization of V-Pits Forming in Gan for No2 Detection at Room Temperature

Based on the special physical and chemical nature of gallium nitride (GaN), such as high electron mobility, wide band gap and strong chemical stability, it displays immense potential in the field of gas detection. Herein, abundant V-pits on GaN ( V-GaN) were successfully fabricated by KOH etching to develop a highly selective and stable NO2 gas sensors with low resistance and working temperature. A satisfying pit density and size by merely regulating the etch time from 10 to 60 min. Meanwhile, the the structural and morphological properties of V-GaN gas sensors were characterized through several techniques. The V-GaN gas sensor under treatment time of 50 min demonstrates highest response, faster response/recovery speeds and lower limit of detection at room temperature (RT). This phenomenon is mainly due to the fact that optimal surface-active sites and maximal specific area of V-GaN with KOH with 50 min. The sensor maintains the well limit of detection and response even in spite of high relative humidity to NO2 gas. Additionally, the V-GaN sensor with KOH for 50 min exhibited outstanding selectivity and long-term stability. This work proposes a new technique for realizing high-performance NO2 detection based on GaN material.Based on the special physical and chemical nature of gallium nitride (GaN), such as high electron mobility, wide band gap and strong chemical stability, it displays immense potential in the field of gas detection. Herein, abundant V-pits on GaN (V-GaN) were successfully fabricated by KOH etching to develop a highly selective and stable NO2 gas sensors with low resistance and working temperature. A satisfying pit density and size by merely regulating the etch time from 10 to 60 min. Meanwhile, the the structural and morphological properties of V-GaN gas sensors were characterized through several techniques. The V-GaN gas sensor under treatment time of 50 min demonstrates highest response, faster response/recovery speeds and lower limit of detection at room temperature (RT). This phenomenon is mainly due to the fact that optimal surface-active sites and maximal specific area of V-GaN with KOH with 50 min. The sensor maintains the well limit of detection and response even in spite of high relative humidity to NO2 gas. Additionally, the V-GaN sensor with KOH for 50 min exhibited outstanding selectivity and long-term stability. This work proposes a new technique for realizing high-performance NO2 detection based on GaN material.