Kichul Lee, Minhyun Kim, Yeongjae Kwon, Seyeon Park, Yunsung Lim, Do Y. Kwak, Jaeseok Jeong, Baul Kim, Jaewan Ahn, Jihan Kim, Yong‐Hoon Cho, Il‐Doo Kim, Inkyu Park
Light-activated gas sensors offer a low-temperature, low-power approach for detecting target species, and their high-performance capabilities make them ideal for practical applications. The direct integration of Bi-doped In 2 O 3 nanofibers onto micro light-emitting diode (μLED) platforms enables high-performance sensors for simultaneous NO 2 and H 2 O detection. Introducing Bi into In 2 O 3 matrices facilitates the formation of oxygen vacancies and the dissociative adsorption of H 2 O, enhancing the adsorption and reactions with NO 2 . Under blue illumination, this μLED sensor system exhibits high NO 2 sensitivity, with a response value ( R g / R a ) of 264.9 at 1 ppm and 60% relative humidity and response and recovery times of less than 30 s. The use of μLEDs enhances light activation with a high energy transfer efficiency, resulting in outstanding NO 2 sensing characteristics. A convolutional neural network-based algorithm is employed to analyze transient sensing signals, accurately predicting with 99% classification accuracy and 10% regression error for both NO 2 and H 2 O, thereby demonstrating weather-independent sensing. This integration of Bi-doped In 2 O 3 nanofibers, which are specifically activated by blue illumination, μLEDs, and deep learning analytics, enables highly effective real-time environmental monitoring of NO 2 and humidity under environmentally variable outdoor conditions.