Hot Electrons Near-infrared Photodetector Based On Chiral Nano-antennas

Circularly polarized light detectors can play an important role in optical communications,medical and pharmaceutical,and information processing fields.The traditional detection of circularly polarized light is compo sed of multiple discrete optical components,and its using environments are greatly restricted.Circularly polarized light detectors based on semiconductors have shown a good momentum of development due to their small size,low power consumption,and compa tibility with integrated circuits.At present,most circularly polarized light detectors are mainly hot electronic devices designed by using chiral metamaterials to selectively absorb circularly polarized light.Although this type of circularly polarized l ight detector has stable working performance and unique advantages in integration and miniaturization,it faces the bottleneck that the photoelectric respons ivity is difficult to improve,and its working performance is easily limited by the responsivity.Aiming at this limitation,this paper proposes a new type of photodetector device,which can detect circularly polarized light through the direction of the photocurrent,so that it can still achieve better detection performance at a lower responsivity.In this thesis,the selective absorption of circularly polarized light by chiral metamaterials can generate hot electrons.These hot electrons are efficiently collected by the collecting electrode and form a photocurrent with a certain specific direction.The polarization direction of circularly polarized light can be distinguished by the difference in the direction of the photocurrent.This article mainly proposes three devices,namely left-handed chiral nanoantenna devices,right-handed chiral nanoantenna devices,and chiral nanoantenna optimized devices.The left-handed chiral nanoantenna device can detect left-handed circularly polarized light sensitively,and the right-handed chiral nanoantenna device can detect right-handed circularly polarized light sensitively,and the chiral nanoantenna optimized device can detect both left-handed circularly polarized light and right-handed circularly polarized light.The paper uses FDTD Solution simulation software to model the device and analyze the photoelectric performance.This kind of device achieves a responsivity near 1.9m A/W when left-handed circularly polarized light or right-handed circularly polarized light is incident and can perform circularly polarized light detection better.The device designed in this paper uses silicon as the base material,which has great potential for integration and miniaturization.This new detection method that uses the direction of the photocurrent to identify circularly polarized light provides a new idea for circularly polarized light detection and has a positive reference significance.