Metamaterial perfect absorber-enhanced plasmonic photo-thermoelectric conversion

Perfect absorption is key to achieving high responsivity of a thin-film photodetector. Here, we report the effect of a metamaterial perfect absorber on the external quantum efficiency of plasmonic photo-thermoeletric conversion, which is a photodetection method based on local heating. The photodetector with a metamaterial perfect absorber shows strong absorption, resulting in external quantum efficiency about three times of that of a control device. Plasmon-induced local temperature rise contributes to the photodetection, and its amplitude is examined both experimentally and numerically.