A filterless, visible-blind, narrow-band, and near-infrared photodetector with a gain. Issue 26 (15th June 2016)

• Record Type: Journal Article
• Authors: Shen, Liang; Zhang, Yang; Bai, Yang; Zheng, Xiaopeng; Wang, Qi; Huang, Jinsong
• Is Part Of: Nanoscale. Volume 8:Issue 26(2016)
• Page Start: 12990
• Page End: 12997
• Publication Date: 2016-06-15
• Subjects: Nanoscience -- Periodicals; Nanotechnology -- Periodicals; 620.505
• DOI: 10.1039/c6nr02902g
• Languages: English
• ISSNs: 2040-3364

Abstract

Abstract : The hole trap induced electron injection improves the responsivity by >10 fold to achieve narrow-band NIR detection. Abstract : In many applications of near-infrared (NIR) light detection, a band-pass filter is needed to exclude the noise caused by visible light. Here, we demonstrate a filterless, visible-blind, narrow-band NIR photodetector with a full-width at half-maximum of <50 nm for the response spectrum. These devices have a thick (>4 μm) nanocomposite absorbing layers made of polymer–fullerene:lead sulfide (PbS) quantum dots (QDs). The PbS QDs yield a photoconductive gain due to their hole-trapping effect, which effectively enhances both the responsivity and the visible rejection ratio of the external quantum efficiency by >10 fold compared to those without PbS QDs. Encouragingly, the inclusion of the PbS QDs does not increase the device noise. We directly measured a noise equivalent power (NEP) of 6.1 pW cm −2 at 890 nm, and a large linear dynamic range (LDR) over 11 orders of magnitude. The highly sensitive visible-blind NIR narrow-band photodetectors may find applications in biomedical engineering.