Nanometer-Scale Photodetectors for High Performance and Unique Functionality

As opposed to the case with MOSFETs widely used in the very-large-scale integrated circuit, miniaturization of the photodetectors to the nanometer scale does not always lead the performance improvement mainly due to the reduced thickness and area for the light absorption. However, it is still possible to circumvent the drawback by introducing the optical antenna and to improve the performance by miniaturization. Moreover, the nanometer-scale photodetectors exhibits unique functionalities such as incident angle detection and biosensing. In this report, some examples found in the photodiode with SP antenna, MOSFET single-photon detector, SET-based ultrahigh-frequency rectifier, and terahertz bolometer are introduced.