Highly Sensitive Ammonia Gas Sensing up to PPB Region based on a Carbazole-Triazine Derivative

Ammonia gas sensors have been found widespread applications in industries, agriculture, environmental monitoring, automotive emissions control, and medical diagnosis. In this study, we report the development of a highly sensitive ammonia gas sensor using 2,4-diphenyl-6-bis(12-phenylindolo)[2,3-a]carbazole-11-yl)-1,3,5-triazine (DIC-TRZ), a common host material used in thermally activated delayed fluorescence organic light-emitting diodes, in a vertical nanojunction device structure. We also demonstrate the successful implementation of a p-type doping strategy to enhance the operation current during gas sensing. Our results indicate that DIC-TRZ is a promising material for highly sensitive room temperature ammonia gas sensing. The sensor exhibits a low detection limit in the ppb-range, fast response and recovery time, and stable operational current, making it highly potential for environmental, occupational, and personal health monitoring applications.