Lead-Free CsCu2I3 Perovskite Nanostructured Networks Gas Sensor for Selective Detection of Trace Nitrogen Dioxide at Room Temperature

The development of low power consumption sensing devices for detecting trace toxic gases is imperative for a wide variety of applications. Recently, hybrid organic–inorganic lead perovskite-based sensors have been fabricated to demonstrate their potential for gas sensing application. However, the poor repeatability and toxicity of lead halide perovskites severely restrict their further practical applications. Here, the lead-free all-inorganic cesium copper iodide (CsCu ₂ I ₃ ) perovskite nanostructured networks are deposited onto interdigital electrodes patterned substrate as the gas sensitive layer via simply spin coating the precursors. The sensor exhibites excellent room temperature NO ₂ sensing properties, including ultra-low limit of detection, excellent repeatability, and good selectivity. Dynamic testing displays the good cycling repeatability of the sensor for ppb level NO ₂ . The ultra-sensitive NO ₂ sensing behavior of the CsCu ₂ I ₃ nanostructure networks are mainly attributed to the unique nanoneedle clusters network structure and large amount of cation vacancies on the perovskite surface. In conclusion, the high sensitivity and environmentally friendly CsCu ₂ I ₃ sensor shows great potential for trace indoor pollutants detection and breathe analysis for disease diagnosis.