Article
Chemistry, Multidisciplinary
Liang Gao, Chao Feng, Yongfu Li, Xiaohan Chen, Qingpu Wang, Xian Zhao
Summary: This paper investigates a metal-graphene metamaterial device that exhibits a tunable, electromagnetically induced transparency (EIT) spectral response at terahertz frequencies. The device structure, composed of a strip and a ring resonator, induces the EIT effect by serving as the bright and dark mode, respectively. By utilizing the variable conductivity of graphene to dampen the dark resonator, the device can dynamically shift its response frequency over 100 GHz, satisfying the requirement for convenient post-fabrication tunability. The proposed device also exhibits slow-light behavior with a maximum group delay of 1.2 ps. Moreover, the sensing performance is studied, showing a sensitivity of up to 100 GHz/(RIU) and a figure of merit (FOM) value exceeding 4 RIU-1. Therefore, the graphene-based metamaterial provides a new miniaturized platform to facilitate the development of terahertz modulators, sensors, and slow-light applications.
Article
Engineering, Electrical & Electronic
Tingting Lang, Zhenyu Yu, Jinhui Zhang, Zhi Hong, Jianjun Liu, Ping Wang
Summary: This study designs and theoretically analyzes a new type of sensor based on electromagnetically induced transparency metamaterials. The proposed metamaterial sensor consists of a polyimide substrate at the bottom and a periodic aluminum structure on the top. CST STUDIO SUITE is used to determine the transmission spectrum of the metamaterials in the terahertz band. The simulation results show that the sensitivity of the metamaterial sensor reaches 270.4 GHz/RIU. The metamaterial sensor is then fabricated to detect bovine serum albumin with a sensitivity of 15.390 GHz/(mg/mL) and a limit of detection (LOD) of 8.97 μg/mL in the concentration range of 0-10 mg/mL. The proposed sensor has the advantages of incident-angle insensitivity, polarization insensitivity, and small size, making it suitable for various research fields including physics, biology, and chemical sensing.
SENSORS AND ACTUATORS A-PHYSICAL
(2023)
Article
Physics, Condensed Matter
Hanqing Dong, Chengjing Gao, Li Zeng, Dan Zhang, Haifeng Zhang
Summary: This study proposes an electromagnetically induced transparency (EIT) metamaterial based on the bright-dark-quasi-dark theory, which achieves the transition from EIT to electromagnetically induced absorption (EIA) by adjusting the coupling distance. By adding nested split-ring resonators (SRRs), substantial absorption enhancement is achieved, and the structure also exhibits polarization-insensitive characteristics. The influences of different structural parameters on absorption performance are further discussed.
PHYSICA B-CONDENSED MATTER
(2022)
Article
Engineering, Electrical & Electronic
Mingming Chen, Zhongyin Xiao, Fei Lv, Zhentao Cui, Qidi Xu
Summary: A simple and multi-layer metamaterial made of graphene is proposed to achieve excellent manipulation of the EIT-like effect. By adjusting the Fermi level of graphene, tunable EIT-like effect can be obtained. In addition, wideband EIT-like effect with high transmission can be achieved by adjusting the geometrical parameters of the metamaterial.
IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS
(2022)
Article
Optics
Tingling Lin, Yi Huang, Shuncong Zhong, Yujie Zhong, Zhenghao Zhang, Qiuming Zeng, Yingjie Yu, Zhike Peng
Summary: THz metamaterial sensing is an emerging technology in biomedical sciences with unique characteristics. This study reports an innovative method of manipulating the electric field to enhance liquid sensing at THz frequencies, which holds bright promises for real-time monitoring of trace biomolecules.
OPTICS AND LASERS IN ENGINEERING
(2022)
Article
Chemistry, Physical
Jin Zhang, Zhenfei Li, Linda Shao, Fajun Xiao, Weiren Zhu
Summary: The study demonstrates the active modulation of EIT analog by integrating graphene into a microwave metamaterial for the first time, showing that the EIT peak can be dynamically controlled under a relatively low bias voltage applied on graphene. The continuous tuning of the EIT resonance strength is achieved by variably dampening the dark resonator using graphene.
Article
Optics
Feng Wen, Shaowei Zhang, Sijia Hui, Hanghang Ma, Sijia Wang, Huapeng Ye, Wei Wang, Tianfei Zhu, Yanpeng Zhang, Hongxing Wang
Summary: This article reports on a method of inducing a tunable THz lattice in magnetized monolayer graphene through interference of optical beams. By manipulating the optical parameters, the optical properties of the induced lattice can be efficiently tuned, and adjustable effects are observed in far-field diffraction. The research provides a versatile tool for all-optical switching at the few photons level and paves the way for the development of next generation high-speed wireless communication.
Article
Physics, Multidisciplinary
Tingling Lin, Yi Huang, Shuncong Zhong, Manting Luo, Yujie Zhong, Yingjie Yu, Jian Ding
Summary: The research proposed a metamaterial sensor utilizing electromagnetically induced transparency resonance, which enhances the interaction between light and matter through substrate etching, leading to significantly improved sensitivity and potential applications in biosensing.
FRONTIERS IN PHYSICS
(2021)
Article
Engineering, Electrical & Electronic
Song Wang, Shuang Wang, Xiaoli Zhao, Jianyu Zhu, Quan Li, Tai Chen
Summary: The study introduces and fabricates J-shaped planar structure metasurfaces to achieve dual-frequency toroidal dipole resonances and electromagnetically induced transparency effect in the terahertz band. By coupling two asymmetric J-shaped metal rings, low-frequency and high-frequency toroidal dipole resonances are simultaneously excited, creating a transparent window. The resonant response of the toroidal dipole can be adjusted by structural parameters, showing sensing characteristics of the metasurfaces, providing potential for the development of terahertz functional devices.
JOURNAL OF INFRARED MILLIMETER AND TERAHERTZ WAVES
(2021)
Article
Nanoscience & Nanotechnology
Yuze Hu, Mingyu Tong, Siyang Hu, Weibao He, Xiang'ai Cheng, Tian Jiang
Summary: The study presents a dual-optically tunable metaphotonic device for ultrafast terahertz switching. It achieves picosecond ultrafast photoswitching with 100% modulation depth at either 0.55 THz or 0.86 THz, controlled by continuous wave light and femtosecond laser pulse. The technology enables frequency-selective, temporally tunable, and multidimensionally-driven features, making it valuable for advanced multiplexing of information and wireless communication.
Article
Multidisciplinary Sciences
Angana Bhattacharya, Rakesh Sarkar, Naval K. Sharma, Bhairov K. Bhowmik, Amir Ahmad, Gagan Kumar
Summary: This study introduces a novel metamaterial geometry for multiband transparency in the terahertz domain, utilizing strong near field coupling between toroidal excitation and C-resonators to achieve multiple transparency windows. High Q factor resonances are reported, and the frequency modulation of transparency windows by changing the distance between TSRR and C resonators is demonstrated. The study has the potential to impact the development of terahertz photonic components for next generation devices.
SCIENTIFIC REPORTS
(2021)
Article
Engineering, Electrical & Electronic
Kai-Da Xu, Shengpei Xia, Yijun Cai, Jianxing Li, Jianlei Cui, Chengying Chen, Jianmei Zhou
Summary: A tunable electromagnetic induced transparency (EIT)-like metamaterial structure based on graphene is proposed and analyzed in the terahertz regime. The structure consists of a split-ring resonator and twofolded-line pair resonators, serving as the quasi-dark mode and bright mode, respectively. The frequency of the transparency window can be adjusted by changing the Fermi energy level of graphene. The physical mechanism of EIT-like phenomenon is explained using a coupled two-oscillator model, which attributes it to the near-field coupling effect between the bright and quasi-dark modes.
MICROWAVE AND OPTICAL TECHNOLOGY LETTERS
(2022)
Article
Optics
Kuan Liu, Xieyu Chen, Meng Lian, Jingyuan Jia, Ying Su, Haonan Ren, Shoujun Zhang, Yihan Xu, Jiajia Chen, Zhen Tian, Tun Cao
Summary: Metasurface analog of electromagnetically induced transparency (EIT) provides a compact platform for generating a narrow-band transmission window with very sharp spectral features. Researchers have experimentally realized the reversible switching of metasurface-induced transparency in the THz spectrum by integrating a nonvolatile phase change material into the meta-atoms. The proposed reconfigurable THz metadevices may provide a new route for ultrafast laser induced switching and reconfigurable slow-light devices.
LASER & PHOTONICS REVIEWS
(2022)
Article
Optics
Yuze Hu, Mingyu Tong, Zhongjie Xu, Xiangai Cheng, Tian Jiang
Summary: This study introduces a novel spatiotemporal metadevice for terahertz wave manipulation with ultra-high spatial and ultrafast temporal control, exhibiting bistability and erasable logic operations. By leveraging both spatial and temporal degrees of freedom, it lays the foundation for enhancing optical computing, data storage, and ultrahigh-speed information processing capabilities.
LASER & PHOTONICS REVIEWS
(2021)
Article
Nanoscience & Nanotechnology
Ming Hua, Yuanbo Sun, Meiping Li, Zizheng Liu, Yu Chen, Yanpeng Shi, Yafei Ning, Yifei Zhang, Fuhua Yang, Xiaodong Wang
Summary: A novel electromagnetic induced transparency (EIT) analog is proposed and demonstrated numerically in the terahertz region using hybrid metal-dielectric metamaterials. The EIT analog, consisting of a metal bar and a silicon disk, achieves high transmission with a Q-factor of approximately 250 through destructive interference between localized surface plasmon resonance and anapole modes. The hybrid metamaterial's performance is influenced by background index and silicon disk radius, and it also shows potential for integration into microfluidic chips for various sensing applications.
Article
Optics
Chang Liu, Shuimei Ding, Qianlei Tian, Xitong Hong, Wanhan Su, Lin Tang, Liming Wang, Mingliang Zhang, Xingqiang Liu, Yawei Lv, Johnny C. Ho, Lei Liao, Xuming Zou
Summary: This study proposes a new device that combines optoelectronic memory and a detector, allowing for switchable functions. The device has long storage time, high on/off ratio, and excellent multi-bit storage in the memory mode. In the detector mode, it exhibits fast response, impressive responsivity, and self-driven broadband detection. Additionally, the device has the ability to quickly resolve polarization in the near-infrared range.
LASER & PHOTONICS REVIEWS
(2023)
Article
Chemistry, Multidisciplinary
Pengshan Xie, Xu Chen, Zixin Zeng, Wei Wang, You Meng, Zhengxun Lai, Quan Quan, Dengji Li, Weijun Wang, Xiuming Bu, Sai-Wing Tsang, SenPo Yip, Jia Sun, Johnny C. C. Ho
Summary: This paper proposes large-scale artificial synaptic device arrays based on organic molecule-nanowire heterojunctions with tunable photoconductivity, which can mimic and realize the functions of visual systems. These devices have tunable photoconductivity and response to multiple wavelengths, which can improve the recognition rate of neural networks.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Weijun Wang, You Meng, Yuxuan Zhang, Zhuomin Zhang, Wei Wang, Zhengxun Lai, Pengshan Xie, Dengji Li, Dong Chen, Quan Quan, Di Yin, Chuntai Liu, Zhengbao Yang, SenPo Yip, Johnny C. Ho
Summary: Atomically 2D layered ferroelectric semiconductor bismuth oxychalcogenides (Bi2O2Se) with a thickness of 7.3 nm and a piezoelectric coefficient (d(33)) of 4.4 +/- 0.1 pm V-1 is investigated. The random orientations and electrically dependent polarization of the dipoles are uncovered, and the interplay between ferroelectricity and semiconducting characteristics in Bi2O2Se is explored on device-level operation, showing hysteresis behavior and memory window formation. Leveraging the ferroelectric polarization, the fabricated device exhibits smart photoresponse tunability and excellent electronic characteristics.
ADVANCED MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
You Meng, Yuxuan Zhang, Zhengxun Lai, Wei Wang, Weijun Wang, Yezhan Li, Dengji Li, Pengshan Xie, Di Yin, Dong Chen, Chuntai Liu, SenPo Yip, Johnny C. Ho
Summary: Converting vapor precursors to solid nanostructures via a liquid noble-metal seed is a common vapor deposition principle. However, such a noble-metal-seeded process is excluded from the crystalline halide perovskite synthesis, mainly hindered by the growth mechanism shortness. In this work, the Au-seeded CsPbI3 nanowires growth is realized based on a vapor-liquid-solid (VLS) growth mode powered by a spontaneous exothermic nucleation process, contributing to outstanding photodetector performances.
Article
Chemistry, Physical
Dong Chen, Shaoce Zhang, Di Yin, Wanpeng Li, Xiuming Bu, Quan Quan, Zhengxun Lai, Wei Wang, You Meng, Chuntai Liu, SenPo Yip, Fu-Rong Chen, Chunyi Zhi, Johnny C. C. Ho
Summary: This study reports a method to tailor the interlayer spacing of 2D SnS nanosheets, which enhances the chemical affinity towards NO3- and NO2- while inhibiting hydrogen generation. This promotes the rate-determining step in electrochemical nitrate reduction to ammonia and achieves excellent Faradaic efficiency and yield rate.
ADVANCED ENERGY MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Dengji Li, You Meng, Yuxuan Zhang, Pengshan Xie, Zixin Zeng, Wei Wang, Zhengxun Lai, Weijun Wang, Sai-Wing Tsang, Fei Wang, Chuntai Liu, Changyong Lan, SenPo Yip, Johnny C. Ho
Summary: The surface of low-dimensional perovskites is crucial for determining their intrinsic properties, and understanding their characteristics and the influence of specific surfaces is valuable for designing functional surface-engineered structures. Surface passivation can also be used to stabilize and optimize perovskite-based optoelectronics. In this study, cesium lead bromide (CsPbBr3) microwire parallel arrays with specific (100)-terminated crystal planes were fabricated, showing excellent photodetection performance and long-term environment stability (>3000 h). It was found that environmental oxygen can passivate Br-vacancy-related trap states on the (100) surface and create charge carrier nanochannels to enhance the (opto)electronic properties. The coupling effects between oxygen species and the specific terminated crystal planes of perovskites highlight the importance of surface engineering for designing and optimizing perovskite-based devices.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Jiajia Zha, Shuhui Shi, Apoorva Chaturvedi, Haoxin Huang, Peng Yang, Yao Yao, Siyuan Li, Yunpeng Xia, Zhuomin Zhang, Wei Wang, Huide Wang, Shaocong Wang, Zhen Yuan, Zhengbao Yang, Qiyuan He, Huiling Tai, Edwin Hang Tong Teo, Hongyu Yu, Johnny C. Ho, Zhongrui Wang, Hua Zhang, Chaoliang Tan
Summary: In this work, an electronic/optoelectronic memory device based on tellurium-based 2D van der Waals heterostructure is reported. It features both long-term and short-term memory behaviors using electrical and optical pulses in the short-wave infrared (SWIR) region. This device enables a fully memristive in-sensor RC system for optical fiber signal processing.
ADVANCED MATERIALS
(2023)
Article
Chemistry, Physical
Zhengxun Lai, Yuxuan Zhang, You Meng, Xiuming Bu, Wei Wang, Pengshan Xie, Weijun Wang, Chuntai Liu, SenPo Yip, Johnny C. Ho
Summary: This study reports a new type of electrode, metalloid electrode, which is more stable than conventional noble metals as electrical contacts for halide perovskites. The degradation mechanism of noble metal electrodes compared to metalloid electrodes is investigated, and it is found that noble metals are prone to halogenation in halide perovskites, while metalloid electrodes remain intact after long-term storage. Furthermore, the long-time operation stability of perovskite devices with metalloid electrodes is higher than that of noble metals. First-principles calculations confirm the exceptional stability of metalloid electrodes.
Article
Chemistry, Physical
Yezhan Li, Zhengxun Lai, You Meng, Wei Wang, Yuxuan Zhang, Xuwen Zhao, Di Yin, Weijun Wang, Pengshan Xie, Quan Quan, SenPo Yip, Johnny C. Ho
Summary: Organic-inorganic halide perovskite is a low-cost and solution-processable material with remarkable optoelectronic properties, making it an ideal candidate for high-performance photodetectors and reduce device costs.
JOURNAL OF MATERIOMICS
(2023)
Review
Chemistry, Multidisciplinary
You Meng, Weijun Wang, Wei Wang, Bowen Li, Yuxuan Zhang, Johnny Ho
Summary: This article reviews the advances in anti-ambipolar heterojunctions and highlights their significance in materials, devices, circuits, and broad-scale research.
ADVANCED MATERIALS
(2023)
Article
Physics, Applied
Jiajia Zha, Handa Liu, Huide Wang, Siyuan Li, Haoxin Huang, Yunpeng Xia, Chen Ma, Peng Yang, Zhuomin Zhang, Zhengbao Yang, Ye Chen, Johnny C. C. Ho, Chaoliang Tan
Summary: A plasma-optimized contact strategy was reported to improve the performance of PdSe2 nanoflake-based field-effect transistors (FETs).
APPLIED PHYSICS LETTERS
(2023)
Article
Materials Science, Multidisciplinary
Rui Zhang, Zhuojun Yang, Liwen Liu, Jie Lin, Shaofeng Wen, You Meng, Yi Yin, Changyong Lan, Chun Li, Yong Liu, Johnny C. Ho
Summary: This study reports highly sensitive, broadband, and flexible PdSe2 thin film photodetectors on PI substrates that can detect light from UV to infrared regions. The devices with thick PdSe2 films exhibit good performance, with a responsivity of 37.6 mA W-1 at 1550 nm and a fast response time. The thin PdSe2 film shows both positive and negative photoresponses in the infrared region, and the negative photoresponse in the UV to VIS region is attributed to charge transfer-related adsorption-desorption of gas molecules.
ADVANCED OPTICAL MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Huide Wang, Haoxin Huang, Jiajia Zha, Yunpeng Xia, Peng Yang, Yonghong Zeng, Yi Liu, Rui Cao, Bing Wang, Wei Wang, Long Zheng, Ye Chen, Qiyuan He, Xing Chen, Ke Jiang, Ja-Hon Lin, Zhe Shi, Johnny C. Ho, Han Zhang, Chaoliang Tan
Summary: A tellurium (Te)-based infrared photodetector is reported with a specifically designed asymmetric electrical contact area, achieving low dark current and high sensitivity at room temperature.
ADVANCED OPTICAL MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Qing Tong, Jensen Li, Shubo Wang
Summary: This research investigates the circular dichroism effect in acoustic systems. It is found that the effect is negligible in lossy metamaterials with C4 rotational symmetry but can be strongly enhanced in C2-symmetric systems with inhomogeneous loss. This enhancement is attributed to the presence of polarization band gaps and non-Hermitian exceptional points.
Article
Nanoscience & Nanotechnology
Pengfei Zhao, Liyou Luo, Yongquan Liu, Jensen Li
Summary: This study develops a transformation theory for manipulating the illusion effects of flexural waves. By introducing tailor-made thickness profiles on different curved shapes, the flexural waves can propagate in a way that is different from the actual configuration. Numerical simulations and experimental mapping confirm the effectiveness of this approach and reveal its potential applications in structural designs.
