Plasmonic-Resonant Bowtie Antenna for Carbon Nanotube Photodetectors

Abstract

The design of bowtie antennas for carbon nanotube (CNT) photodetectors has been investigated. CNT photodetectors have shown outstanding performance by using CNT as sensing element. However, detection wavelength is much larger than the diameter of the CNT, resulting in small fill factor. Bowtie antenna can confine light into a subwavelength volume based on plasmonic resonance, thus integrating a bowtie antenna to CNT photodetectors can highly improve photoresponse of the detectors. The electric field enhancement of bowtie antennas was calculated using the device geometry by considering fabrication difficulties and photodetector structure. It is shown that the electric field intensity enhancement increased exponentially with distance reduction between the CNT photodetector to the antenna. A redshift of the peak resonance wavelength is predicted due to the increase of tip angles of the bowtie antennas. Experimental results showed that photocurrent enhancement agreed well with theoretical calculations. Bowtie antennas may find wide applications in nanoscale photonic sensors.

Plasmonic-enhanced carbon nanotube infrared bolometers

“…Alternatively, plasmonic materials have provided a potential approach to enhancing the performance of IR detectors by the integration of active materials into plasmonic structures [21][22][23][24]. Application of plasmonic nanoantennas has also been investigated in various CNT-and graphene-based devices, to manipulate and enhance their performance characteristics [25][26][27][28]. These plasmonic structures derive their properties from light-coupled collective oscillation of conduction electrons along the medium interface, known as the localized surface plasmons.…”

Single wall carbon nanotube based optical rectenna

“…When the light interacts with optical antennas with specific dimensions, surface plasmons are generated and only at resonant frequency, light will be absorbed and irradiated. 42 This dependence of the device current on the length of the CNT provide potential design opportunities for antennas at a different wavelength. Moreover, for our source, the photon energy lies in the range 1.24 eV and 2.48 eV.…”

Gate dependent photo-responses of carbon nanotube field effect phototransistors

“…The quantum efficiency of the AM-FEP at V gs = −3 V is around 3%. This quantum efficiency is relatively large considering the diameter of the SWCNT (∼1 nm), and can be potentially improved by diminishing the size incompatibility between the micro-sized wavelength and the nano-sized absorption area using an optical antenna [26,27].…”