A Transparent Nanopatterned Chemiresistor: Visible‐Light Plasmonic Sensor for Trace‐Level NO<sub>2</sub> Detection at Room Temperature
Kyeorei Lim, Young‐Moo Jo, Ji‐Wook Yoon, Jun‐Sik Kim, Dong‐Jae Lee, Young Kook Moon, Jiwon Yoon, Jaehyeok Kim, Hun Ji Choi, Jong‐Heun Lee
Abstract
Abstract The highly selective detection of trace gases using transparent sensors at room temperature remains challenging. Herein, transparent nanopatterned chemiresistors composed of aligned 1D Au–SnO 2 nanofibers, which can detect toxic NO 2 gas at room temperature under visible light illumination is reported. Ten straight Au–SnO 2 nanofibers are patterned on a glass substrate with transparent electrodes assisted by direct‐write, near‐field electrospinning, whose extremely low coverage of sensing materials (≈0.3%) lead to the high transparency (≈93%) of the sensor. The sensor exhibits a highly selective, sensitive, and reproducible response to sub‐ppm levels of NO 2 , and its detection limit is as low as 6 ppb. The unique room‐temperature NO 2 sensing under visible light emanates from the localized surface plasmonic resonance effect of Au nanoparticles, thereby enabling the design of new transparent oxide‐based gas sensors without external heaters or light sources. The patterning of nanofibers with extremely low coverage provides a general strategy to design diverse compositions of gas sensors, which can facilitate the development of a wide range of new applications in transparent electronics and smart windows wirelessly connected to the Internet of Things.