Visible‐Blind, Narrowband Sb₂Se₃ Photodiodes Based on Inverted Structure for Flame Detection

Abstract Narrowband detection is in urgent demand across various fields, which has been realized via charge collection narrowing for solution‐processed materials. However, it requires relatively thick absorbing layer, increasing the complexity of fabrication. In this work, an inverted device structure combined with P‐type Sb 2 Se 3 active layer to fabricate narrowband photodetector is employed, in which the unbalanced charge transport leads to wavelength‐dependent photogenerated carrier collection. This approach achieves visible‐blind near‐infrared narrowband photodetectors with relatively thin active layer thickness. The optimized devices exhibit excellent performance metrics, including relatively low dark current and noise, high specific detectivity > 10 11 Jones, and fast response time of 655 ns. More importantly, the devices are successfully applied for flame detection, demonstrating great potential for practical applications.