Article
Chemistry, Physical
Janusz Andrzejewski, Mieczyslaw Antoni Pietrzyk, Dawid Jarosz, Adrian Kozanecki
Summary: This paper investigates the photoluminescence spectra of excitons in ZnO/ZnMgO/ZnO double asymmetric quantum wells. The presence of an internal electric-field band structure lowers the energy of quantum states and allows for the spatial separation of electrons and holes in wide quantum wells, forming indirect excitons. The study uses single particle states in the wurtzite structure and a self-consistent model to calculate excitons with 2D hydrogenic 1s-like wave functions.
Article
Materials Science, Multidisciplinary
O. Ruiz-Cigarrillo, L. F. Lastras-Martinez, E. A. Cerda-Mendez, G. Flores-Rangel, C. A. Bravo-Velazquez, R. E. Balderas-Navarro, A. Lastras-Martinez, N. A. Ulloa-Castillo, K. Biermann, P. Santos
Summary: This study investigated in-plane optical anisotropies in symmetric and asymmetric double quantum wells using reflectance anisotropy spectroscopy. It was found that a reduction in symmetry from D-2d to C-2v leads to an increase in reflectance anisotropy strength due to heavy- and light-hole mixing. Residual anisotropies in symmetric DQWs originate from QW interface asymmetry, while in asymmetric DQWs, the asymmetrical distribution of AlGaAs layers contributes to the increased RAS intensity.
Article
Chemistry, Multidisciplinary
Kaiyuan Yao, Mary S. Collins, Kara M. Nell, Edward S. Barnard, Nicholas J. Borys, Tevye Kuykendall, J. Nathan Hohman, P. James Schuck
Summary: This study examines the strongly excitonic optical properties of 2D semiconductors, specifically focusing on silver selenide monolayers. The research demonstrates the potential of utilizing multiquantum-well structures for enhancing light matter interactions and constructing optoelectronic and quantum excitonic devices. The efficient blue photoluminescence and ultrafast exciton radiative dynamics of the material highlight its promising characteristics for various applications.
Article
Chemistry, Multidisciplinary
Megan O. Hill, Paul Schmiedeke, Chunyi Huang, Siddharth Maddali, Xiaobing Hu, Stephan O. Hruszkewycz, Jonathan J. Finley, Gregor Koblmueller, Lincoln J. Lauhon
Summary: This study successfully correlates the morphology, strain, defects, and emission characteristics of quantum wells in nanowires under specific geometries using 3D Bragg coherent diffraction imaging technique, revealing the limits of elastic strain accommodation.
Article
Chemistry, Multidisciplinary
Christoph Kastl, Adam M. Schwartzberg, Lorenzo Maserati
Summary: Metal-organic species can self-assemble into large-scale, atomically defined supramolecular architectures. In this study, the excited carrier dynamics in a prototypical metal-organic chalcogenide were investigated, revealing a complex relaxation cascade.
Article
Chemistry, Multidisciplinary
Xilong Liang, Chengbing Qin, Yan Gao, Shuangping Han, Guofeng Zhang, Ruiyun Chen, Jianyong Hu, Liantuan Xiao, Suotang Jia
Summary: The study found that the spin-orbit coupling of monolayer MoS2 can be reversibly engineered by laser irradiation under controlled gas environments, where the spin-orbit splitting has been effectively regulated within 140 meV to 200 meV, and the photoluminescence intensity of the B exciton can be reversibly manipulated over 2 orders of magnitude.
Article
Physics, Condensed Matter
V. M. Kovalev, M. Boev, O. Kibis
Summary: Using the Floquet theory, this study developed a method to control the excitonic properties of semiconductor quantum wells through a high-frequency electromagnetic field. It was found that the field induced a blue shift in the exciton emission and narrowed the corresponding spectral line width. This finding has important implications for tuning the characteristics of optoelectronic devices based on quantum wells.
JOURNAL OF PHYSICS-CONDENSED MATTER
(2022)
Article
Crystallography
Jingtao Liu, Shiping Luo, Xiaohui Liu, Ying Wang, Chunsheng Wang, Shufang Wang, Guangsheng Fu, Yuriy Mazur, Morgan E. Ware, Gregory J. Salamo, Baolai Liang
Summary: This research investigates the carrier injection effect in hybrid structures with SQDs coupled to either BQDs or a QW injection layer. The study finds that carrier capture and emission efficiency for SQDs in the BQD injection structure is better than that of the QW injection due to strong coupling between the two QD layers.
Article
Chemistry, Multidisciplinary
Zixi Yin, Jing Leng, Shiping Wang, Guijie Liang, Wenming Tian, Kaifeng Wu, Shengye Jin
Summary: Two-dimensional layered perovskites hold great promise for optoelectronic applications, but are limited in some devices by the lack of carrier transport between quantum wells. This study reports an Auger-assisted electron transfer mechanism between adjacent quantum wells in 2D perovskites, providing a new guideline for designing perovskites with optically tunable charge transport properties.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2021)
Article
Chemistry, Multidisciplinary
Thomas F. K. Weatherley, Wei Liu, Vitaly Osokin, Duncan T. L. Alexander, Robert A. Taylor, Jean-Francois Carlin, Raphael Butte, Nicolas Grandjean
Summary: This study demonstrates the successful spatial resolution and analysis of nonradiative point defects in InGaN/GaN quantum wells using high-resolution cathodoluminescence. The different types of point defects were identified by contrasting behaviors and their densities were measured from 10^14 cm^-3 to as high as 10^16 cm^-3. The results show the interplay between point defects and carrier dynamics, highlighting the impact of point defects on carrier diffusion lengths and nonradiative behaviors.
Article
Chemistry, Physical
Paulina Jaimes, Tsumugi Miyashita, Tian Qiao, Kefu Wang, Ming Lee Tang
Summary: In this work, nanocrystals with an inner InP shell were used for triplet-triplet annihilation-based photon upconversion. The InP-based nanocrystals are earth-abundant and can be synthetically tuned to absorb in the NIR window. A two monolayer ZnS shell was used to passivate surface defects and improve the photoluminescence quantum yield of the InP nanocrystals. The ZnSe/InP/ZnS nanocrystals showed promising results in photon upconversion and can potentially convert NIR photons to visible light.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Chemistry, Physical
Paulina Jaimes, Tsumugi Miyashita, Tian Qiao, Kefu Wang, Ming Lee Tang
Summary: In this study, an inverse Type-I heterostructure with an inner InP shell was used for triplet-triplet annihilation-based photon upconversion. The addition of a ZnS shell on ZnSe/InP core/shell particles increased the photoluminescence quantum yield and transmitter triplet lifetime, while decreasing the rate of triplet energy transfer. The photon upconversion quantum yield of the ZnSe/InP/ZnS nanocrystals was found to be around 4.0%, suggesting their potential for converting near-infrared photons to visible light.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Chemistry, Multidisciplinary
Partha Kumbhakar, Abhirup Roy Karmakar, Gour Prasad Das, Jayjeet Chakraborty, Chandra S. Tiwary, Pathik Kumbhakar
Summary: The reversible temperature-dependent PL emission quenching properties of Mn2+-doped ZnS QDs have been utilized for the development of a smartphone-based optical thermometer. By studying the temperature-dependent variations of PL, the technique has been successfully applied in polymer films and validated through thermal cycling experiments and the use of a custom Android App for temperature measurement.
Article
Materials Science, Multidisciplinary
Aurelia Chenu, Shiue-Yuan Shiau, Ching-Hang Chien, Monique Combescot
Summary: In this study, we investigate the strong coupling between photons and excitonic excitations in a coupled quantum well under the presence of an electric field. We demonstrate the transition from a hybrid polariton, composed of a photon coupled to hybrid carriers in two wells, to a dipolariton, composed of a photon coupled to direct and indirect excitons, with an increase in the field strength. We also explore how the cavity photon lifetime and the coherence time of the carrier wave vectors affect these polaritonic states through non-hermitian Hamiltonians. While the hybrid polaritons exhibit a spectral singularity known as an exceptional point, depending on detuning and lifetimes, we find that the three dipolaritonic states display an anticrossing without an exceptional point due to the interaction among photons, direct, and indirect excitons.
Review
Chemistry, Physical
Tsukasa Torimoto, Tatsuya Kameyama, Taro Uematsu, Susumu Kuwabata
Summary: I-III-VI multinary semiconductors, with low toxicity, are being studied as potential quantum dot materials to replace toxic Cd and Pb-based binary semiconductors. The flexibility in design and control of electronic and optical properties of multinary quantum dots has attracted significant attention. This review provides a historical overview of the synthesis of I-III-VI quantum dots and discusses strategies for better control of their optoelectronic properties. Applications in luminescent devices and light energy conversion systems are also discussed, highlighting the potential for improved performance by controlling the size and composition of the quantum dots. Understanding the unique features of I-III-VI quantum dots will enable the development of novel applications utilizing their complexity.
JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY C-PHOTOCHEMISTRY REVIEWS
(2023)
