A CuO thin film type sensor via inkjet printing technology with high reproducibility for ppb-level formaldehyde detection

Abstract

High-performance gas sensors have huge application prospects and consumer demands in environmental monitoring, public security and other fields. Nevertheless, the conductive type metal oxide gas sensors prepared by traditional coating or dropping technology encounter challenges in low detection limit and excellent replication, hardly meeting the actual needs of trace harmful gas detection and mass production. Here, a uniform and high-quality CuO sensing film is formed quickly and efficiently by inkjet printing technology, which is expected to realize mass preparation of high-performance formaldehyde sensors. The CuO sensor can reach as low as 50 ppb formaldehyde detection limit, satisfying the monitor needs of the World Health Organization’s specified value 80 ppb. In addition, the gas sensors in each batch exhibit outstanding repeatability and stability with small deviation, and the relative mean deviations toward formaldehyde in the aspect of response, response and recovery times are all about only 5% between batches. The controllable micro-nano-level film thickness and uniform surface achieved by inkjet printing technology are the compelling reasons for low detection limit and superb reproducibility of gas sensors. Our work can offer a theoretical and experimental basis for large-scaled production of high-performance gas sensors from research to practical application.