Towards high performance visible-blind narrowband near-infrared photodetectors with integrated perovskite light filter

Abstract

Narrowband near-infrared (NIR) light detection is essential for optical imaging, machine vision, and spectroscopy. In this work, we demonstrate a strategy towards visible-blind narrowband NIR organic photodetectors by integrating perovskite thin film as the light filter. Lead phthalocyanine (PbPc):Fullerene (C60) bulk heterojunction which demonstrates high efficiency in photoexciton dissociation is used as the photosensitive layer due to excellent absorption of PbPc in NIR light region. Perovskite layer which has a strong absorption in the visible region but a weak absorption in the NIR region serves as a light filtering layer. More importantly, we have further improved the device performance by inserting copper phthalocyanine (CuPc) electron blocking layer between the ITO anode and PbPc:C60 bulk heterojunction. A high photoresponsivity (R) of 1.09 A/W, an external quantum efficiency (EQE) of 167%, and a narrow spectral response with the full width of half maximum of ~60 nm for NIR light of 808 nm wavelength is obtained.