Sandwiched PbS/Au/PbS phototransistor for surface plasmon enhanced near-infrared photodetection

Abstract In this work, sandwiched PbS/Au/PbS near-infrared photodetectors were designed and fabricated by a low cost and scalable spin-coating method. Due to the enhancement by surface plasmon of Au nanorods, compared with the individual PbS quantum dot photodetectors, the photodetectors achieved a higher responsivity of 8.2 A W−1, detectivity of 6.3 × 1010 Jones and external quantum efficiency of 1251% under a 5 mW cm−2 light illumination, at a relatively low gate and source-drain bias. The results indicate that the sandwiched PbS/Au/PbS is a promising candidate for photodetection and has great potential for optoelectronic devices.