scholarly journals High-Performance Multifunctional Photodetector and THz Modulator Based on Graphene/TiO2/p-Si Heterojunction

2021 ◽  
Author(s):  
Lichuan Jin ◽  
Miaoqing Wei ◽  
Dainan Zhang ◽  
Lei Zhang ◽  
Huaiwu Zhang
Keyword(s):  
High Performance ◽  
Modulation Depth ◽  
Vertical Direction ◽  
Optical Gain ◽  
Terahertz Wave ◽  
Depletion Region ◽  
Semiconductor Diode ◽  
Negative Bias ◽  
Terahertz Waves ◽  
Infrared Band

Abstract In this paper, we have prepared a multifunctional device based on graphene/TiO2/p-Si heterojunction and systematically studied the optical response of the device in the ultraviolet-visible-infrared band and the transmission changes of terahertz waves in the 0.3-1.0 THz band under different bias voltages. As a photodetector, the “back-to-back” p-n-p energy band structure makes the device have a serious unbalanced distribution of photogenerated carriers in the vertical direction when light is incident from the graphene side, which ensures a higher optical gain of the device, so as to achieve a responsivity up to 3.6 A/W and a detectability of 4×1013 Jones under 750 nm laser irradiation. As a terahertz modulator, the addition of the TiO2 layer allows the device to continuously widen the carrier depletion region under negative bias, thereby realizing modulation of the terahertz wave, making the modulation depth up to 23% under − 15 V bias. However, there is almost no change in the transmission of the terahertz wave when positive bias is applied. An analogue of an electronic semiconductor diode effect is realized that allows passage of the terahertz wave only for negative bias and blocks the terahertz wave while positively biased.

scholarly journals High-Performance Multifunctional Photodetector and THz Modulator Based on Graphene/TiO2/p-Si Heterojunction

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Miaoqing Wei ◽  
Dainan Zhang ◽  
Lei Zhang ◽  
Lichuan Jin ◽  
Huaiwu Zhang
Keyword(s):  
High Performance ◽  
Modulation Depth ◽  
Vertical Direction ◽  
Optical Gain ◽  
Terahertz Wave ◽  
Depletion Region ◽  
Semiconductor Diode ◽  
Negative Bias ◽  
Terahertz Waves ◽  
Infrared Band

Abstract In this paper, we have reported a multifunctional device from graphene/TiO2/p-Si heterojunction, followed by its systematical analysis of optical response in a device under ultraviolet–visible-infrared band and transmission changes of terahertz waves in the 0.3–1.0 THz band under different bias voltages. It is found that photodetector in the “back-to-back” p-n-p energy band structure has a seriously unbalanced distribution of photogenerated carriers in the vertical direction when light is irradiated from the graphene side. So this ensures a higher optical gain of the device in the form of up to 3.6 A/W responsivities and 4 × 1013 Jones detectability under 750 nm laser irradiation. Besides, the addition of TiO2 layer in this terahertz modulator continuously widens the carrier depletion region under negative bias, thereby realizing modulation of the terahertz wave, making the modulation depth up to 23% under − 15 V bias. However, almost no change is observed in the transmission of terahertz wave when a positive bias is applied. A similar of an electronic semiconductor diode is observed that only allows the passage of terahertz wave for negative bias and blocks the positive ones. Graphic Abstract

scholarly journals Plasmonic semiconductor nanogroove array enhanced broad spectral band millimetre and terahertz wave detection

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Jinchao Tong ◽  
Fei Suo ◽  
Tianning Zhang ◽  
Zhiming Huang ◽  
Junhao Chu ◽  
...  
Keyword(s):  
Surface Plasmon ◽  
High Performance ◽  
Room Temperature ◽  
Spectral Band ◽  
High Capacity ◽  
Terahertz Wave ◽  
Semiconductor Surface ◽  
Wide Range ◽  
Low Sensitivity ◽  
Air Interfaces

AbstractHigh-performance uncooled millimetre and terahertz wave detectors are required as a building block for a wide range of applications. The state-of-the-art technologies, however, are plagued by low sensitivity, narrow spectral bandwidth, and complicated architecture. Here, we report semiconductor surface plasmon enhanced high-performance broadband millimetre and terahertz wave detectors which are based on nanogroove InSb array epitaxially grown on GaAs substrate for room temperature operation. By making a nanogroove array in the grown InSb layer, strong millimetre and terahertz wave surface plasmon polaritons can be generated at the InSb–air interfaces, which results in significant improvement in detecting performance. A noise equivalent power (NEP) of 2.2 × 10−14 W Hz−1/2 or a detectivity (D*) of 2.7 × 1012 cm Hz1/2 W−1 at 1.75 mm (0.171 THz) is achieved at room temperature. By lowering the temperature to the thermoelectric cooling available 200 K, the corresponding NEP and D* of the nanogroove device can be improved to 3.8 × 10−15 W Hz−1/2 and 1.6 × 1013 cm Hz1/2 W−1, respectively. In addition, such a single device can perform broad spectral band detection from 0.9 mm (0.330 THz) to 9.4 mm (0.032 THz). Fast responses of 3.5 µs and 780 ns are achieved at room temperature and 200 K, respectively. Such high-performance millimetre and terahertz wave photodetectors are useful for wide applications such as high capacity communications, walk-through security, biological diagnosis, spectroscopy, and remote sensing. In addition, the integration of plasmonic semiconductor nanostructures paves a way for realizing high performance and multifunctional long-wavelength optoelectrical devices.

scholarly journals Effective Generation of Milliwatt-Level Sub-Terahertz Wave for Nonlinear Response Measurement of Two-Dimensional Material by Optical Heterodyne Technique

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Shuqing Chen ◽  
Zhiqiang Xie ◽  
Junmin Liu ◽  
Yanliang He ◽  
Yao Cai ◽  
...  
Keyword(s):  
Nonlinear Response ◽  
Modulation Depth ◽  
Terahertz Wave ◽  
Saturable Absorption ◽  
Optical Heterodyne ◽  
Two Dimensional ◽  
Response Measurement ◽  
Microwave Source ◽  
Terahertz Band ◽  
Heterodyne Technique

By using optical heterodyne technique, we demonstrated the stable emission of sub-terahertz wave with the frequency ranging from 88 GHz to 101 GHz, which can operate as microwave source for nonlinear response measurement system. Mutual frequency beating of two well-separated sideband signals at a 0.1 THz photo-detector (PD) allows for the generation of sub-terahertz signal. Based on this approach, we have achieved the radiation of 0.1 THz wave with power up to 4 mW. By transmittance measurement, two-dimensional nanomaterial topological insulator (TI: Bi2Te3) shows saturable absorption behaviors with normalized modulation depth of 47% at 0.1 THz. Our results show that optical heterodyne technique could be developed as an effective microwave source generation for nonlinear measurement at sub-terahertz, even terahertz band.

Terahertz Wave Avalanche Breakdown Transistor for high performance switching

2021 ◽  
Author(s):  
WANG WEIJUN ◽  
Liang-Hui Du ◽  
Jiang Li ◽  
PeiRen Tang ◽  
Zhao-Hui Zhai ◽  
...  
Keyword(s):  
High Performance ◽  
Terahertz Wave ◽  
Avalanche Breakdown

NIR Light Driven Terahertz Wave Modulator with a Large Modulation Depth Based on a Silicon‐PEDOT:PSS‐Perovskite Hybrid System

2020 ◽  
Vol 5 (4) ◽  
pp. 1901090
Author(s):  
Weien Lai ◽  
Chengda Ge ◽  
Hao Yuan ◽  
Qingfeng Dong ◽  
Deren Yang ◽  
...  
Keyword(s):  
Hybrid System ◽  
Modulation Depth ◽  
Terahertz Wave ◽  
Nir Light

scholarly journals A New Electro-Optical Switch Modulator Based on the Surface Plasmon Polaritons of Graphene in Mid-Infrared Band

Sensors ◽  
2018 ◽  
Vol 19 (1) ◽  
pp. 89 ◽  
Author(s):  
Ming Cai ◽  
Shulong Wang ◽  
Bo Gao ◽  
Yindi Wang ◽  
Tao Han ◽  
...  
Keyword(s):  
Energy Loss ◽  
Surface Plasmon ◽  
Surface Plasmon Polaritons ◽  
Surface Plasmon Polariton ◽  
Modulation Depth ◽  
Optical Switch ◽  
Dielectric Structure ◽  
Infrared Band ◽  
Mid Infrared ◽  
Plasmon Polaritons

In this paper, a new electro-optical switch modulator based on the surface plasmon polaritons of graphene is proposed. An air–graphene-substrate–dielectric structure is adopted in the modulator. In this structure, the graphene is considered as a film of metal whose thickness tends to be infinitesimal. By changing the external voltage, the boundary conditions can be changed to decide whether the surface plasmon polariton waves can be excited in mid-infrared band. Because of this effect, the structure can be used as an electro–optical switch modulator, whose modulation depth is about 100% in theory. Finally, the 3 dB bandwidth (~34 GHz) and the energy loss (36.47 fJ/bit) of the electro–optical switch modulator are given, whose low energy loss is very suitable for engineering applications.

scholarly journals Dual-band dichroic asymmetric transmission of linearly polarized waves in terahertz chiral metamaterial

Nanophotonics ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 3235-3242 ◽  
Author(s):  
Tingting Lv ◽  
Xieyu Chen ◽  
Guohua Dong ◽  
Meng Liu ◽  
Dongming Liu ◽  
...  
Keyword(s):  
High Performance ◽  
Light Propagation ◽  
Polarization State ◽  
Dual Band ◽  
Terahertz Waves ◽  
Asymmetric Transmission ◽  
Polarized Waves ◽  
Wide Range ◽  
Linearly Polarized ◽  
Chiral Metamaterial

AbstractPolarization conversion dichroism is of particular interest in manipulating the polarization state of light, whereas high-performance asymmetric transmission (AT) of linearly polarized waves is still inaccessible in the terahertz range. Here, a bilayer chiral metamaterial consisting of orthogonally chained S-shaped patterns with broken symmetry along the light propagation direction is proposed and demonstrated experimentally to realize a dual-band dichroic AT effect for linearly polarized terahertz waves. The AT effects are robust across a wide range of incident angles. The observed strong AT can be theoretically explained by a multiple reflection and transmission interference model and the transfer matrix method. The proposed bilayer chiral metamaterial may have broad applications in polarization manipulation, chiral biosensing and direction-dependent information processing.

scholarly journals New aspects of improving the performance of WO3 thin films for photoelectrochemical water splitting by tuning the ultrathin depletion region

RSC Advances ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 899-905 ◽  
Author(s):  
Jiajie Cen ◽  
Qiyuan Wu ◽  
Danhua Yan ◽  
Wenrui Zhang ◽  
Yue Zhao ◽  
...  
Keyword(s):  
Thin Films ◽  
Water Splitting ◽  
High Performance ◽  
Depletion Region ◽  
Photoelectrochemical Water Splitting ◽  
Surface Modulation ◽  
Wo3 Thin Films

Surface modulation approach offers an effective and scalable method for high-performance WO3 photoanodes.

High Performance Zinc Oxide Thin Film Transistors Through Improved Material Processing and Device Design

2014 ◽  
Author(s):  
Ahmad Hossein Adl ◽  
Samira Farsinezhad ◽  
Alex Ma ◽  
Douglas W. Barlage ◽  
Karthik Shankar
Keyword(s):  
Thin Film ◽  
Thin Film Transistors ◽  
High Performance ◽  
Schottky Contact ◽  
Depletion Region ◽  
Charge Carriers ◽  
Oxide Thin Film ◽  
Zinc Oxide Thin Film ◽  
Poor Control ◽  
High Throughput Method

Solution processing (SP) is a cheap, simple and high-throughput method for the fabrication of ZnO thin film transistors (TFTs). Lack of enhancement mode operation, poor crystallinity, traps, and poor control of the carrier concentration are some of the disadvantages of this method. The high intrinsic electron concentration of SP-ZnO makes saturation of TFTs non-trivial. We report on Schottky barrier thin film transistors (SB-TFT). By biasing the source Schottky contact in reverse bias, a depletion region is formed around the source contact hence depleting the region from the free charge carriers which produces the saturation of the device. The effect of the Schottky contact is illustrated by comparing the operation of SB-TFTs with that of conventional TFTs.

Sign in / Sign up

Export Citation Format

Share Document