A filterless, visible-blind, narrow-band, and near-infrared photodetector with a gain

作者：Shen Liang; Zhang Yang; Bai Yang; Zheng Xiaopeng; Wang Qi; Huang Jinsong

来源：Nanoscale, 2016, 8(26): 12990-12997.

DOI：10.1039/c6nr02902g

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 mu m) 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.

• 出版日期2016