Article
Chemistry, Multidisciplinary
Savas Delikanli, Furkan Isik, Emek G. Durmusoglu, Onur Erdem, Farzan Shabani, Betul Canimkurbey, Satish Kumar, Hamed Dehghanpour Baruj, Hilmi Volkan Demir
Summary: This study demonstrates the achievement of optical gain in an aqueous medium using specially designed heterostructured quantum wells, opening up possibilities for bio-optoelectronic applications.
Article
Physics, Applied
Roni Shaashoua, Alberto Bilenca
Summary: Stimulated Brillouin scattering (SBS) microscopy is a promising method for mechanical imaging in biological settings. Experimental measurements and theoretical predictions show that increasing numerical aperture (NA) in SBS microscopy leads to a decrease in Brillouin frequency shift and peak gain, as well as broadening and distortion of the Brillouin linewidth. These effects can limit the precision and accuracy of spectral parameter retrieval in biological systems.
APPLIED PHYSICS LETTERS
(2023)
Article
Chemistry, Multidisciplinary
Zhangshun Li, Yexin Jiang, Zuanming Jin, Zhuoyi Li, Xianyang Lu, Zhijiang Ye, Jin-Yi Pang, Yongbing Xu, Yan Peng
Summary: Due to its high sensitivity and independence of magneto-optical response, terahertz emission spectroscopy has become a powerful tool for studying ultrafast demagnetization and spin current dynamics in nanometer-thick ferromagnetic/heavy metal heterostructures. By manipulating the order of conductive coatings and considering charge equilibration, we can determine the contributions of different dipole moments and directly observe the coupled spin and charge dynamics.
Article
Chemistry, Physical
Zhilong Zhang, Jooyoung Sung, Daniel T. W. Toolan, Sanyang Han, Raj Pandya, Michael P. Weir, James Xiao, Simon Dowland, Mengxia Liu, Anthony J. Ryan, Richard A. L. Jones, Shujuan Huang, Akshay Rao
Summary: This study reveals the exciton dynamics in quantum dot solids using transient absorption microscopy and observes the changes and transitions in initial exciton diffusion. The spacing between quantum dots, packing density, and heterogeneity all have an impact on exciton dynamics. These findings contribute to the control of optoelectronic properties in quantum dot solids.
Article
Materials Science, Multidisciplinary
Yang Liu, Yingtian Xu, Chongyang Xu, Jiahao Chen, Heng Liu, He Zhang, Liang Jin, Jie Fan, Yonggang Zou, Xiaohui Ma
Summary: In this study, a Ti3C2Tx/graphene vertical heterostructure (TG-VHS) is successfully used as a saturable absorber (SA) to generate femtosecond laser pulses via passive mode-locking, demonstrating the potential of MXenes-based heterostructures for ultrafast photonics. The study provides an important strategy for developing VHS SAs for ultrafast pulse fiber lasers and opens new perspectives for designing advanced MXenes-based photonic devices.
ADVANCED OPTICAL MATERIALS
(2023)
Article
Chemistry, Physical
Kseniia A. Sergeeva, Kezhou Fan, Aleksandr A. Sergeev, Sile Hu, Haochen Liu, Christopher C. Chan, Stephen V. Kershaw, Kam Sing Wong, Andrey L. Rogach
Summary: We investigated the charge carrier dynamics in HgTe quantum dots emitting in the second near-infrared window and found that the exchange of ligands significantly affects the Auger recombination rate and the performance of HgTe-based thin film photodetectors.
JOURNAL OF PHYSICAL CHEMISTRY C
(2022)
Article
Physics, Applied
Daniel Burt, Hyo-Jun Joo, Youngmin Kim, Yongduck Jung, Melvina Chen, Manlin Luo, Dong-Ho Kang, Simone Assali, Lin Zhang, Bongkwon Son, Weijun Fan, Oussama Moutanabbir, Zoran Ikonic, Chuan Seng Tan, Yi-Chiau Huang, Donguk Nam
Summary: GeSn alloys are a promising technology for photonics and electronics. By using a geometric strain-inversion technique, researchers have successfully converted the harmful compressive strain into beneficial tensile strain in GeSn nanowires, thereby improving the directness of the band structure and enhancing photoluminescence. This work provides a flexible method for developing scalable band-engineered GeSn nanowire devices and creates opportunities for studying materials with tensile strain.
APPLIED PHYSICS LETTERS
(2022)
Article
Optics
Yexin Jiang, Zhangshun Li, Zhuoyi Li, Zuanming Jin, Xianyang Lu, Yongbing Xu, Yan Peng, Yiming Zhu
Summary: The dynamic control of magnetization by short laser pulses has attracted recent interest. The transient magnetization at the metallic magnetic interface has been investigated using second-harmonic generation and the time-resolved magneto-optical effect. However, the ultrafast light-driven magneto-optical nonlinearity in ferromagnetic heterostructures for terahertz (THz) radiation remains unclear. In this study, we demonstrate THz generation from a metallic heterostructure, Pt/CoFeB/Ta, with contributions from magnetization-induced optical rectification and spin-to-charge current conversion.
Article
Optics
Ziyu Wang, Wenqi Xu, Jingle Wei, Jiaming Jiang, Juan Du, Bo Li, Weimin Liu
Summary: This paper introduces a novel time-resolved photoluminescence spectroscopy technique, femtosecond two pulses induced stimulated emission spectroscopy, to study the ultrafast dynamics of stimulated emission process in semiconductor materials. The feasibility of the technique is demonstrated with easy setup and high time resolution.
OPTICS COMMUNICATIONS
(2021)
Article
Optics
M. Plankl, P. E. Faria Junior, F. Mooshammer, T. Siday, M. Zizlsperger, F. Sandner, F. Schiegl, S. Maier, M. A. Huber, M. Gmitra, J. Fabian, J. L. Boland, T. L. Cocker, R. Huber
Summary: Ultrafast nano-videography of tunneling processes in insulators is achieved using terahertz near-field microscopy, probing the local polarizability of electron-hole pairs with evanescent terahertz fields with subcycle temporal resolution. This contact-free nanoscopy technique shows potential for studying ultrafast transport processes in a wide range of condensed matter systems, as demonstrated in van der Waals heterobilayers.
Article
Chemistry, Multidisciplinary
Jonas E. Zimmermann, Marleen Axt, Fabian Mooshammer, Philipp Nagler, Christian Schueller, Tobias Korn, Ulrich Hoefer, Gerson Mette
Summary: Two-dimensional transition metal dichalcogenides provide an intriguing platform for creating van der Waals heterojunctions with unique physical properties. Photoexcited electrons and holes can separate through interfacial charge transfer due to their type-II band alignment. The dynamics of ultrafast charge transfer in these heterostructures, influenced by stacking angle, suggest that radiative recombination becomes the dominant decay route.
Article
Chemistry, Multidisciplinary
Yiqing Shu, Zijun Zhong, Chunyang Ma, Penglai Guo, Leiming Wu, Zhitao Lin, Xun Yuan, Jianqing Li, Weicheng Chen, Quanlan Xiao
Summary: In this research, a two-dimensional BP/InSe heterostructure was successfully fabricated and its optical properties were studied. By preparing an SA based on BP/InSe, stable soliton pulses and harmonic mode locking were achieved. The findings demonstrate the potential of 2D BP/InSe heterostructure in the applications of nano-photonics devices.
Article
Chemistry, Multidisciplinary
Xueqiong Su, Yong Pan, Dongwen Gao, Jin Wang, Ruixiang Chen, Yimeng Wang, Xin-yu Yang, Li Wang
Summary: This study investigates the ultrafast modulation process and physical mechanism of graphene quantum dots on the optical properties of CsPbBr3 quantum dots, achieving the best modulation effect at a drop volume of 0.05 mL.
Article
Optics
Muhammad Anisuzzaman Talukder, Paul Dean, Edmund H. Linfield, A. Giles Davies
Summary: This study introduces a THz QCL heterostructure designed to emit two resonant photons from each electronic relaxation between two same-parity states, predicting a significant enhancement of light intensity compared to conventional THz QCL structures through simulations.
Review
Optics
Jiaqi Zhou, Weiwei Pan, Weiao Qi, Xinru Cao, Zhi Cheng, Yan Feng
Summary: Ultrafast Raman fiber lasers are effective for obtaining ultrafast optical pulses at specific wavelengths, but generating pulses with high energy and short duration is challenging compared to conventional rare-earth doped lasers. This review discusses three categories of ultrafast Raman fiber laser technologies and their advantages and challenges. A newly developed technology called nonlinear optical gain modulation (NOGM) is introduced as a simple and high-quality solution for generating high-energy femtosecond pulses with wavelength agility.
Article
Materials Science, Multidisciplinary
Jing Liu, Pieter Geiregat, Luca Pilia, Rik Van Deun, Flavia Artizzu
Summary: This study investigates the energy transfer pathways from dyes to lanthanide nanoparticles using a combination of photoluminescence and transient absorption spectroscopy. By selecting small-sized dye molecules with localized molecular orbitals close to the nanoparticle surface, exceptionally high efficiency in lanthanide nanoparticles sensitization can be achieved.
ADVANCED OPTICAL MATERIALS
(2021)
Article
Nanoscience & Nanotechnology
Stijn Jooken, Yovan de Coene, Olivier Deschaume, Daniel Zambo, Tangi Aubert, Zeger Hens, Dirk Dorfs, Thierry Verbiest, Koen Clays, Geert Callewaert, Carmen Bartic
Summary: The research demonstrates that the electric field sensitivity of fluorescence intensity of type-I and quasi-type-II quantum dots and quantum rods is enhanced under two-photon excitation, allowing them to track fast switching E-fields. This suggests the potential of semiconductor nanoparticles as cellular voltage probes in multiphoton imaging.
Article
Chemistry, Multidisciplinary
Tangi Aubert, Aleksandr A. Golovatenko, Margarita Samoli, Laurent Lermusiaux, Thomas Zinn, Benjamin Abecassis, Anna Rodina, Zeger Hens
Summary: This paper proposes a new sizing function based on proportional correction for nonparabolic bands, which allows for the prediction of size quantization in colloidal quantum dots. Using known bulk parameters, the size quantization of different materials can be predicted.
Article
Chemistry, Multidisciplinary
Ivo Tanghe, Justinas Butkus, Kai Chen, Ronnie R. Tamming, Shalini Singh, Yera Ussembayev, Kristiaan Neyts, Dries van Thourhout, Justin M. Hodgkiss, Pieter Geiregat
Summary: The refractive index change of 2D semiconductors is crucial for realizing various photonic devices. By utilizing femtosecond interferometry and effective medium algorithm, the time-dependent refractive index of colloidal 2D materials can be measured and calculated, showing significant phase modulation due to excitonic features.
Article
Chemistry, Multidisciplinary
Matthias Ruppert, Hanh Bui, Laxmi Kishore Sagar, Pieter Geiregat, Zeger Hens, Gabriel Bester, Nils Huse
Summary: Femtosecond pump-probe spectroscopy was used to investigate ultrafast carrier dynamics in mid-infrared HgTe nanoparticles, revealing intraband relaxation processes ranging from resonant excitation to multi-exciton generation after photoexcitation. The study elucidates the earliest dynamics below 10 ps in this material and finds long carrier relaxation times as high as 2.1 ps in the multi-exciton generation regime close to the particles' ionization threshold, with a constant mean carrier energy dissipation rate of 0.36 eV ps(-s) extracted for all photon energies.
Editorial Material
Chemistry, Physical
Tangi Aubert, Aleksandr A. Golovatenko, Anna V. Rodina, Zeger Hens
CHEMISTRY OF MATERIALS
(2022)
Article
Materials Science, Multidisciplinary
Ivo Tanghe, Jordi Llusar, Juan Climente, Alex Barker, Giuseppe Paterno, Francesco Scotognella, Anatolii Polovitsyn, Ali Hossain Khan, Zeger Hens, Dries Van Thourhout, Pieter Geiregat, Iwan Moreels
Summary: By using CdSe/CdS nanocrystals with closely spaced hole levels and sparse electron states, a continuous broadband gain spectrum can be achieved, which is significant for photonics applications.
ADVANCED OPTICAL MATERIALS
(2022)
Article
Materials Science, Multidisciplinary
Filipe Sousa Velosa, Hannes van Avermaet, Pieter Schiettecatte, Leila Mingabudinova, Pieter Geiregat, Zeger Hens
Summary: This study investigates the properties of photo-excited InP/ZnSe quantum dots using femtosecond transient absorption spectroscopy. It is found that with increasing exciton number, the band-edge bleach evolves and net stimulated emission is observed. The lower-than-expected gain threshold is explained by considering the Stokes shift between band-edge absorption and emission.
ADVANCED OPTICAL MATERIALS
(2022)
Article
Chemistry, Physical
P. Tim Prins, Dirk A. W. Spruijt, Mark J. J. Mangnus, Freddy T. Rabouw, Daniel Vanmaekelbergh, Celso de Mello Donega, Pieter Geiregat
Summary: Impurity doping of III-V colloidal quantum dots remains underexplored. This study shows that electron cooling is fast in copper-doped InP quantum dots, while hole localization is slow but still leads to efficient luminescence.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2022)
Article
Optics
Mohammad Mohammadimasoudi, Pieter Geiregat, Frederik Van Acker, Jeroen Beeckman, Zeger Hens, Tangi Aubert, Kristiaan Neyts
Summary: In this study, a vertical cavity surface emitting laser utilizing colloidal quantum dots and chiral liquid crystal as optical materials is demonstrated to achieve stable and long-term narrow-linewidth lasing. The flexible device can also act as a sensor in different solvents and the lasing wavelength can be adjusted through pressure, strain, or temperature.
LIGHT-SCIENCE & APPLICATIONS
(2022)
Article
Chemistry, Multidisciplinary
Carmelita Roda, Pieter Geiregat, Alessio Di Giacomo, Iwan Moreels, Zeger Hens
Summary: In this study, we used cross-polarized pump-probe spectroscopy to measure the absorption coefficient spectrum of the exciton-biexciton transition in colloidal CdSe nanoplatelets (NPLs) and determined the biexciton oscillator strength (fBX). We found that fBX is independent of the NPL area and agrees with predictions of a short-range interaction model.
Article
Chemistry, Multidisciplinary
Aleksandr A. A. Golovatenko, Ina V. V. Kalitukha, Grigorii S. S. Dimitriev, Victor F. F. Sapega, Maxim V. V. Rakhlin, Aidar I. I. Galimov, Tatiana V. V. Shubina, Elena V. V. Shornikova, Gang Qiang, Dmitri R. R. Yakovlev, Manfred Bayer, Amelie Biermann, Axel Hoffmann, Tangi Aubert, Zeger Hens, Anna V. V. Rodina
Summary: This paper investigates the influence of the crystal structure on the band-edge exciton fine structure in spheroidal CdSe nanocrystals. The study compares zinc blende and wurtzite CdSe nanocrystals using fluorescence line narrowing and time-resolved photoluminescence techniques. The results suggest that the nanocrystal shape and shape dispersion contribute to the energy splitting between bright and dark exciton states in both crystal structures.
Article
Nanoscience & Nanotechnology
Resul Ozdemir, Hannes Van Avermaet, Onur Erdem, Pieter Schiettecatte, Zeger Hens, Tangi Aubert
Summary: Quantum dots (QDs) are extensively used as light emitters in photonic and optoelectronic applications. To prevent degradation of their optical properties, QDs must be encapsulated between barrier layers to shield them from oxygen and water vapor. A new approach for direct patterning of QDs through maskless lithography has been developed.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Chemistry, Multidisciplinary
Jacob A. Erstling, Nirmalya Bag, Thomas C. Gardinier, Ferdinand F. E. Kohle, Naedum Domnwachukwu, Scott D. Butler, Teresa Kao, Kai Ma, Melik Z. Turker, Grant B. Feuer, Rachel Lee, Nada Naguib, James F. Tallman, Henry F. Malarkey, Lieihn Tsaur, William L. Moore, Dana V. Chapman, Tangi Aubert, Saurabh Mehta, Richard A. Cerione, Robert S. Weiss, Barbara A. Baird, Ulrich B. Wiesner
Summary: The study examines the interactions of fluorescent and poly(ethylene glycol)-coated (PEGylated) core-shell silica nanoparticles with biological barriers during oral delivery. It finds that ultra-small nanoparticles below 10 nm diameter passively pass through tight junctions, while particles above 20 nm diameter are actively transported through cells. Additionally, the in vivo experiments in mice demonstrate successful passage through the body and renal clearance without protein corona formation, suggesting the nanoparticles as viable candidates for oral administration.
ADVANCED MATERIALS
(2023)