Article
Materials Science, Multidisciplinary
Tingting Liu, Cheng Zhang, Xiaofeng Li
Summary: The fundamental processes of hot-carrier in 2D MXenes (Mo2C and Ti3C2) were studied using first-principles calculation. It was found that Mo2C and Ti3C2 have higher hot-carrier generation efficiencies than Au for energies over 1 eV. Biaxial strain was used to optimize the hot-carrier transport properties of Mo2C. A Mo2C/MoGeSiN4 hot-electron photodetector was proposed, showing a significantly higher responsivity compared to existing hot-carrier devices.
ADVANCED OPTICAL MATERIALS
(2022)
Article
Chemistry, Physical
Wenjun Wu, Dongze Li, Yuehua Xu, Xiao Cheng Zeng
Summary: The 2D tetrahex-GeC2 materials exhibit novel electronic properties and highly anisotropic carrier transport behavior under different strains, showing potential applications in nanoelectronics.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2021)
Article
Optics
Weijia Shao, Weihao Cui, Junhui Hu, Yongmei Wang, Jian Tang, Xiaofeng Li
Summary: We designed a planar hot-electron photodetector with polarity-switchable photocurrent controlled by the working wavelength. By altering the wavelength, the photocurrent polarity of the device can be switched, providing a new approach for flexible hot-electron photodetection.
Review
Physics, Applied
Yisong Zhu, Hongxing Xu, Peng Yu, Zhiming Wang
Summary: Recent studies have shown that hot carriers from nonradiative decay of surface plasmons can be used for photodetection, overcoming the bandgap limitation in semiconductors. However, the major issue with plasmonic hot carrier photodetectors is the low quantum efficiency. Recent engineering progress includes optical antenna-based detectors, planar detectors, detectors coupled with 2D materials, etc.
APPLIED PHYSICS REVIEWS
(2021)
Article
Physics, Multidisciplinary
Kun Ni, Jinxiang Du, Jin Yang, Shujuan Xu, Xin Cong, Na Shu, Kai Zhang, Aolei Wang, Fei Wang, Liangbing Ge, Jin Zhao, Yan Qu, Kostya S. Novoselov, Pingheng Tan, Fuhai Su, Yanwu Zhu
Summary: Through experiments and simulations, researchers have revealed the significant contributions of interlayer shear and breathing modes coupled with in-plane vibration modes to the faster hot-carrier relaxations in bilayer graphene under pressure. This study highlights the importance of understanding the effect of interlayer interaction on the behaviors of electrons and phonons for tailoring the photocarrier dynamic properties of bilayer graphene.
PHYSICAL REVIEW LETTERS
(2021)
Article
Nanoscience & Nanotechnology
Wenrui Zhang, Wei Wang, Jinfu Zhang, Tan Zhang, Li Chen, Yu Zhang, Yanwei Cao, Li Ji, Jichun Ye
Summary: By establishing a low-defect diffusion barrier, the responsivity and response time of ε-Ga2O3 MSM photodetectors were improved simultaneously.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Nanoscience & Nanotechnology
Yajin Dong, Jiaxiang Li, Wenyue Liang, Xianghong Nan, Long Wen, Qin Chen
Summary: Copper-silicon heterojunctions show higher responsivity and longer cutoff wavelength compared to gold-silicon heterojunctions in the sub-bandgap wavelength range of silicon. The advanced photodetection performance of copper-silicon devices is attributed to the relatively higher electron density of state above the Fermi level and the higher ejection probability.
Article
Nanoscience & Nanotechnology
Chiara Trovatello, Giulia Piccinini, Stiven Forti, Filippo Fabbri, Antonio Rossi, Sandro De Silvestri, Camilla Coletti, Giulio Cerullo, Stefano Dal Conte
Summary: Charge transfer processes in 2D van der Waals heterostructures enable upconversion of low energy photons and efficient extraction of charge carriers. In this study, the dynamics of charge transfer in large-area 2D heterostructures made of epitaxial WS2 grown on graphene were investigated using ultrafast optical spectroscopy. The results showed that selective carrier photoexcitation in graphene resulted in an almost instantaneous bleaching of the WS2 excitonic peaks in the visible range, indicating interlayer charge transfer. The transfer of hot carriers generated in graphene to the semiconducting layer was found to occur within a sub-20-fs timescale. The findings have both fundamental and technological importance for the development of novel 2D photodetectors.
NPJ 2D MATERIALS AND APPLICATIONS
(2022)
Article
Multidisciplinary Sciences
Gang Wang, Tanghao Liu, Bingzhe Wang, Hao Gu, Qi Wei, Zhipeng Zhang, Jun He, Mingjie Li, Guichuan Xing
Summary: This study investigates the role of hot-carrier effect in tuning the nonlinear absorption response in quasi-2D perovskite films. By observing the unusual conversion from reverse saturable absorption to saturable absorption, the authors reveal the important role of ultrafast carrier cooling in enabling this abnormal nonlinear absorption conversion process.
NATURE COMMUNICATIONS
(2022)
Article
Multidisciplinary Sciences
Fang Li, Mingxing Chen, Yajuan Wang, Xiaoli Zhu, Xuehong Zhang, Zixing Zou, Danliang Zhang, Jiali Yi, Ziwei Li, Dong Li, Anlian Pan
Summary: The controlled synthesis of high-quality ultrathin h-GaTe/MoS2 heterostructures on MoS2 substrate has led to the design of optoelectronic devices with remarkable photoresponsivity and fast photoresponse speed. This study provides insights into the controlled growth of relevant materials and suggests promising applications in future integrated electronic and optoelectronic devices and systems.
Article
Materials Science, Ceramics
Jianjin Chen, Longhai Shen, Dongli Qi, Lijun Wu, Xiang Li, Jianyu Song, Xinglai Zhang
Summary: Al1-xInxN films with tunable bandgaps were synthesized by placing an In sheet on the Al target and adjusting the RF power. The photoresponse wavelengths of the films were broadened from UV to visible light by increasing the In composition, leading to improved photoresponsivity.
CERAMICS INTERNATIONAL
(2022)
Article
Chemistry, Multidisciplinary
Sandeep Kumar Chamoli, Gopal Verma, Subhash C. Singh, Chunlei Guo
Summary: In this study, a hot electron photodetector based on a metal-dielectric-metal cavity using gold and antimony trisulfide phase change material was introduced. The device showed tunable absorption and responsivity in specific spectral ranges through the phase transition of antimony trisulfide. The sensitivity and resonance cavity of the HEPD device can be changed by transitioning from the crystalline to the amorphous phase, achieving high responsivities at specific wavelengths.
Article
Optics
Tangyou Sun, Wenke Song, Zubin Qin, Wenjing Guo, Peihua Wangyang, Zhiping Zhou, Yanrong Deng
Summary: Infrared detection technology is widely used in laser ranging, imaging, night vision, etc. Recent studies have shown that hot carriers generated by surface plasmon decay can be utilized for photodetection beyond the bandgap restriction of semiconductors. This study designed silicon nanopillars and gold film to achieve perfect absorption by generating surface plasmon resonance and Fabry-Perot resonance. Finite Difference Time Domain (FDTD) method was used to calculate the absorption and examine the effects of factors on resonance wavelength and absorption. The results demonstrate the success of achieving near-unity optical absorption using ultrathin plasmonic nanostructures.
Article
Chemistry, Multidisciplinary
Zhijin Xu, Xin Dong, Lei Wang, Huajie Wu, Yi Liu, Junhua Luo, Maochun Hong, Lina Li
Summary: Benefiting from the superior properties of semiconductors and the angle-dependence of the bulk photovoltaic effect, two-dimensional hybrid perovskite ferroelectrics have been developed for sensitive self-powered polarized photodetection. A new ferroelectric material, (BA)2(FA)Pb2I7, showed high thermostability and broad-spectrum adsorption up to 650 nm, enabling ferroelectricity-driven self-powered polarized photodetection and exhibiting remarkable performance. This research will contribute to the development of new ferroelectrics for potential application in a wide range of polarization-based optoelectronics.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Materials Science, Multidisciplinary
L-B Meng, S. Ni, Z. M. Zhang, S. K. He, W. M. Zhou
Summary: By pairing IIIa-VA atom substitution, an ordered boron-phosphorus codoped graphene material with a sizable Dirac cone gap has been successfully achieved, showing unique band topology and superior properties. This material has high carrier mobility and Fermi velocity, along with a more appreciable SOC gap.
JOURNAL OF MATERIALS CHEMISTRY C
(2021)
Article
Engineering, Electrical & Electronic
Suraj P. Khanna, Satish Singh, C. K. Suman, Nandan Kumar, Alok Dabi
Summary: Multilevel non-volatile resistive switching behavior is observed in electronic textile, displaying write-once-read-many (WORM) memory behavior and allowing conduction modulation using a remote current-bias write/input stimulus. Anisotropic current spreading in the textile can be utilized for selective memory writing and emulating neuron-like behavior. The textile also exhibits the reset WORM or ReWORM effect.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2023)
Article
Nanoscience & Nanotechnology
Laurent Boulley, Thomas Maroutian, Paul Goulain, Andrey Babichev, Anton Egorov, Lianhe Li, Edmund Linfield, Raffaele Colombelli, Adel Bousseksou
Summary: We demonstrate low temperature deposition conditions for VO2 phase change material that are compatible with III-V semiconductors used in optoelectronic applications. The VO2 coated thin films grown on GaAs exhibit a 50% change in optical reflectivity and a significant variation in electric conductivity between insulating and metallic states. We also study the functionalization of mid-infrared QCLs with VO2 layers to engineer their laser emission properties.
Article
Physics, Applied
C. Song, M. Salih, L. H. Li, J. Mangeney, J. Tignon, A. G. Davies, E. H. Linfield, S. Dhillon
Summary: By using thin metallic side-absorbers, researchers have successfully suppressed higher-order transverse modes in Terahertz quantum cascade lasers (THz QCLs), allowing the lasers to operate solely on the fundamental transverse mode without sacrificing high power outputs. This breakthrough opens up opportunities for investigating nonlinear THz physical phenomena using THz QCLs as pump sources.
APPLIED PHYSICS LETTERS
(2023)
Article
Optics
Elisa Riccardi, Valentino Pistore, Seonggil Kang, Lukas Seitner, Anna De Vetter, Christian Jirauschek, Juliette Mangeney, Lianhe Li, A. Giles Davies, Edmund H. Linfield, Andrea C. Ferrari, Sukhdeep S. Dhillon, Miriam S. Vitiello
Summary: By using multilayer graphene saturable absorbers, we have successfully demonstrated a self-starting miniaturized short pulse terahertz laser, which utilizes an original device architecture with surface patterning in the entire cavity of a double-metal semiconductor 2.30-3.55 THz wire laser. This compact, all-electronic, all-passive, and inexpensive configuration achieves self-starting pulsed emission with 4.0 ps-long pulses.
Article
Optics
Mayuri Kashyap, Jari Torniainen, Karl Bertling, Urbi Kundu, Khushboo Singh, Bogdan C. Donose, Tim Gillespie, Yah Leng Lim, Dragan Indjin, Lianhe Li, Edmund H. Linfield, A. Giles Davies, Paul Dean, Millicent Smith, Scott Chapman, Aparajita Bandyopadhyay, Amartya Sengupta, Aleksandar D. Rakic
Summary: This study demonstrates the feasibility of using terahertz sensing for monitoring the hydration level of freshly harvested leaves of Celtis sinensis. A imaging platform based on quantum cascade lasers and laser feedback interferometry is employed to produce high resolution terahertz images of the leaves, allowing monitoring of water transport and other changes across the whole leaf. The resulting images are input into a machine learning model to predict relative water content. The technique shows substantial potential in agricultural applications.
Article
Chemistry, Analytical
Khushboo Singh, Aparajita Bandyopadhyay, Karl Bertling, Yah Leng Lim, Tim Gillespie, Dragan Indjin, Lianhe Li, Edmund H. Linfield, A. Giles Davies, Paul Dean, Aleksandar D. Rakic, Amartya Sengupta
Summary: In order to reduce water consumption in agriculture, photonics-based hydration sensing technology has been widely used for non-contact, non-invasive mapping of liquid water in plants. In this study, terahertz (THz) range sensing techniques were employed to map liquid water in leaves of Bambusa vulgaris and Celtis sinensis. Two complementary techniques, THz time-domain spectroscopic imaging and THz quantum cascade laser-based imaging, were utilized. The results provide detailed spatial and temporal information about hydration dynamics and dehydration effects on leaf structure.
Article
Optics
Song Han, Jieyuan Cui, Yunda Chua, Yongquan Zeng, Liangxing Hu, Mingjin Dai, Fakun Wang, Fangyuan Sun, Song Zhu, Lianhe Li, Alexander Giles Davies, Edmund Harold Linfield, Chuan Seng Tan, Yuri Kivshar, Qi Jie Wang
Summary: One of the most exciting breakthroughs in physics is the introduction of topology to photonics, demonstrated by the recently developed topological lasers. This study focuses on the topological bulk quantum cascade laser (QCL) operating in the terahertz (THz) frequency range. The experiment successfully miniaturized the THz QCL and achieved single-mode lasing with high side-mode suppression ratio (SMSR), indicating potential applications in imaging, sensing, and communications.
LIGHT-SCIENCE & APPLICATIONS
(2023)
Article
Multidisciplinary Sciences
Francesco Pisani, Djamal Gacemi, Angela Vasanelli, Lianhe Li, Alexander Giles Davies, Edmund Linfield, Carlo Sirtori, Yanko Todorov
Summary: In this study, a quantum infrared detector operating in the ultra-strong light-matter coupling regime driven by collective electronic excitations is explored. The strong collective electronic resonances are found to optimize photodetectors operating in this regime. These findings introduce a new approach to conceive optoelectronic devices based on the coherent interaction between electrons and photons.
NATURE COMMUNICATIONS
(2023)
Article
Nanoscience & Nanotechnology
Alessandra Di Gaspare, Osman Balci, Jincan Zhang, Adil Meersha, Sachin M. Shinde, Lianhe Li, A. Giles Davies, Edmund H. Linfield, Andrea C. Ferrari, Miriam S. Vitiello
Summary: Graphene, a nonlinear material in the terahertz frequency range, can be controlled through the use of an ionic liquid gate. The study demonstrates the intense absorption nonlinearity of graphene at high frequencies and suggests the possibility of engineering novel structures for light generation at frequencies over 9 THz.
Article
Materials Science, Multidisciplinary
Aleksandar Demic, Alexander Valavanis, Paul Dean, Lianhe Li, A. Giles Davies, Edmund H. Linfield, John Cunningham, James Bailey, Andrey Akimov, Anthony Kent, Paul Harrison
Summary: We present theoretical methods for analyzing acoustic phonon modes in superlattice structures and terahertz quantum-cascade lasers (THz QCLs). Our numerical solution of the acoustic-wave equation agrees well with experimental pump-probe measurements of acoustic resonances in a THz QCL. We predict that the layer structure in THz QCLs can cause up to <^>2 GHz detuning of acoustic mode spacing, which is not observable in analytical models. This effect is most prominent in devices with large and abrupt acoustic mismatch between layers. Using an acoustic deformation potential and density-matrix approach, we analyze electron transport induced by different THz QCL active-region design schemes. We conclude that acoustic modes up to <^>200 GHz can significantly perturb QCL transport, showcasing their potential for ultrafast laser emission modulation.
Article
Multidisciplinary Sciences
Song Han, Yunda Chua, Yongquan Zeng, Bofeng Zhu, Chongwu Wang, Bo Qiang, Yuhao Jin, Qian Wang, Lianhe Li, Alexander Giles Davies, Edmund Harold Linfield, Yidong Chong, Baile Zhang, Qi Jie Wang
Summary: In this study, an electrically pumped topological laser based on photonic Majorana zero mode is implemented on a quantum cascade chip. The laser emits a topologically nontrivial cylindrical vector beam from a terahertz semiconductor laser. This electrically driven topological laser represents an important breakthrough for converting electricity into THz single-mode laser with nontrivial beams.
NATURE COMMUNICATIONS
(2023)