Surface Plasmon-Enhanced Quantum Dot Infrared Photodetector for Detecting Human Body Emitting Infrared Rays by Using Metal Nanograting

Quantum dot infrared photodetector (QDIP) for detecting infrared rays emitted by the human body has attracted more and more attention from scientific researchers all over the world in the past decade. However, low absorption efficiency at the infrared band in the reported detectors as the major challenge still seriously limits their practical applications. In order to overcome the problem, the QDIP device with a new quantum dot structure together with a rectangular and hole metal grating structure was developed to enhance the light absorption performance through the localized surface plasmon resonance (LSPR). The QDIPs can effectively detect three typical infrared peaks emitted by a human body in the range of 20-53.6 THz with absorption rates of greater than 90%. COMSOL simulation results demonstrate that the optimized QDIP can have the maximum photon absorption rate of 94.1%, which is 2.53 times than that of conventional ones without the metal hole structure. The dramatic increase in absorbance can be attributed to the local coupled surface plasmon effect caused by the novel quantum dot structure and the metal grating structure. It is believed that the study could provide a certain theoretical support for developing high performance infrared detector in the field of human sensing application.

Automated summary

Quantum dot infrared photodetector (QDIP) has gained increasing attention in the past decade for detecting infrared rays emitted by the human body. However, low absorption efficiency in the infrared band remains a major challenge for practical applications. To overcome this problem, researchers have developed a QDIP device with a new quantum dot structure and a metal grating structure, which significantly enhances the light absorption performance.