scholarly journals Carbon Nanotube Far Infrared Detectors with High Responsivity and Superior Polarization Selectivity Based on Engineered Optical Antennas

Sensors ◽  
2021 ◽  
Vol 21 (15) ◽  
pp. 5221
Author(s):  
Xiansong Ren ◽  
Zhaoyu Ji ◽  
Binkai Chen ◽  
Jing Zhou ◽  
Zeshi Chu ◽  
...  

Single-wall carbon nanotube (SWCNT) thin films are promising for sensitive uncooled infrared detection based on the photothermoelectric effect. The SWCNT film is usually shaped into a belt and diversely doped to form a p-n junction at the center. Under the illumination of a focused incident light, the temperature gradient from the junction to the contacts leads to photoresponse. When the SWCNTs are aligned in one direction, the photoresponse becomes polarization selective. Although a typical bowtie antenna can improve the responsivity and polarization extinction ratio by deep-subwavelength light focusing, the absolute absorptance of the junction region is only 0.6%. In this work, the antenna was engineered for a higher light coupling efficiency. By integrating a bottom metal plane at a specific distance from the SWCNT film and optimizing the antenna geometries, we achieved ultra-efficient impedance matching between the antenna and the SWCNTs, thus the absorptance of the junction region was further enhanced by 21.3 times and reached 13.5%, which is more than 3 orders of magnitude higher than that of the device without the engineered antenna. The peak responsivity was further enhanced by 19.9 times and responsivity reached 1500 V/W at 1 THz. The resonant frequency can be tuned by changing the size of the antenna. Over the frequency range of 0.5 THz to 1.5 THz, the peak responsivity was further enhanced by 8.1 to 19.9 times, and the polarization extinction ratio was enhanced by 2.7 to 22.3 times. The highest polarization extinction ratio reached 3.04 × 105 at 0.5 THz. The results are based on the numerical simulations of the light and the thermal fields.

Nanoscale ◽  
2020 ◽  
Vol 12 (22) ◽  
pp. 11808-11817
Author(s):  
Binkai Chen ◽  
Zhaoyu Ji ◽  
Jing Zhou ◽  
Yu Yu ◽  
Xu Dai ◽  
...  

The optical antenna integrated aligned carbon nanotube film works as a highly polarization-sensitive far infrared detector with a polarization extinction ratio over 13 600.


Photonics ◽  
2021 ◽  
Vol 8 (6) ◽  
pp. 198
Author(s):  
Geyu Tang ◽  
Huamao Huang ◽  
Yuqi Liu ◽  
Hong Wang

We propose a new compact polarization beam splitter based on the self-collimation effect of two-dimensional photonic crystals and photonic bandgap characteristics. The device is composed of a rectangular air holes-based polarization beam splitting structure and circular air holes-based self-collimating structure. By inserting the polarization beam splitting structure into the self-collimating structure, the TE and TM polarized lights are orthogonally separated at their junction. When the number of rows in the hypotenuse of the inserted rectangular holes is 5, the transmittance of TE polarized light at 1550 nm is 95.4% and the corresponding polarization extinction ratio is 23 dB; on the other hand, the transmittance of TM polarized light is 88.5% and the corresponding polarization extinction ratio is 37 dB. For TE and TM polarized lights covering a 100 nm bandwidth, the TE and TM polarization extinction ratios are higher than 18 dB and 30 dB, respectively. Compared with the previous polarization beam splitters, our structure is simple, the size is small, and the extinction ratio is high, which meets the needs of modern optical communications, optical interconnection, and optical integrated systems.


2015 ◽  
Author(s):  
Huihui Ma ◽  
Xueguang Yuan ◽  
Yangan Zhang ◽  
Yan Hong ◽  
Limeng Wang ◽  
...  

2011 ◽  
Vol 50 (21) ◽  
pp. 4099 ◽  
Author(s):  
John H. Lehman ◽  
Bob Lee ◽  
Erich N. Grossman

2018 ◽  
Vol 8 (12) ◽  
pp. 2369 ◽  
Author(s):  
Jun Cao ◽  
Yuexin Zou ◽  
Xue Gong ◽  
Ruijie Qian ◽  
Zhenghua An

A general approach was developed to fabricate graphene/semiconducting single-wall carbon nanotube (graphene/s-SWCNT) film Schottky junctions on a large scale. The graphene/s-SWCNT film photodiodes array based on the vertically stacked Schottky junction were fabricated. The all-carbon cross-shaped structure consisted of multielement graphene/s-SWCNT Schottky photodiodes and presented a rich collection of electronics and photonics. The as-fabricated carbon-based photodiode presented an ultra-broadband photodetection characteristic with a high responsivity of 1.75 A/W at near-infrared wavelengths and a fast response rise time of 15 μs. The as-fabricated device clearly showed gate-tunable and wavelength-dependent photoelectric characteristic. Moreover, the corresponding photocurrent excitation spectrum was also demonstrated. In particular, the Si compatible and high throughput fabrication process for the devices made it conducive for large-area multielement optoelectronics devices.


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