Silicon-based narrowband photodetectors with blade-coated perovskite light extinction layer for high performance visible-blind NIR detection

Abstract

NIR narrowband imaging is highly desirable for its applications in biological sensing, environmental monitoring and military defense. Unfortunately, it cannot be fulfilled by the most widely used silicon-based photodetectors due to their broadband response. Herein, we present novel silicon-based narrowband photodetectors (Si-NBPDs) with the wavelength response ranging from 800 to 1200 nm, by integrating the perovskite light extinction layer with the Si-based metal–semiconductor-metal photodetectors. The perovskite layer was prepared by a low-cost and scalable methylamine-assisted blading-coating method, and its thickness was comprehensively modulated to achieve the highest visible to NIR rejection ratio up to 120. Impressively, these Si-NBPDs exhibited a high sensitivity with the lowest detectable light intensity down to 200 pW·cm⁻², a fast response speed with rise/fall time of 11/68 µs, and a large liner dynamic range of 120 dB. Furthermore, the proof-of-concept NIR imaging test exhibited that this photodetector was immune to visible background influence, which shows its promising applications in biological fluorescence imaging as the NIR-I&II windows.