Graphene-based midinfrared photodetector with bull's eye plasmonic antenna

The spectral region of midinfrared has proven its great potential in various fields, such as materials characterization, medical examination, security, and product inspection. However, the development of room-temperature sensitive midinfrared photodetectors is inevitably in strong demand. Graphene-based detectors are expected to potentially overcome many of the shortcomings of earlier detectors. Unfortunately, low light absorption originating from a single atomic layer is still an obstacle for sensitive sensing using graphene-based photodetectors. To optimize the performance of plasmonic antenna, we have proposed wideband bull's-eye-shaped antennas using cavity-mode resonance for the midinfrared region. The proposed multi-resonant frequency plasmonic antennas are integrated with graphene-based detectors for midinfrared detection. We demonstrated that the graphene device integrated with the multifrequency plasmonic antenna enabled the room-temperature sensitive midinfrared detection. In addition, such a device can achieve frequency filtering measurement through the bull's eye shaped plasmonic antenna. The coupling of antenna onto the device largely spares the integration space. We believe that such a device is practical in various applications that require room-temperature, frequency selective sensitive photo detection.