In this Letter, we study the diffusion properties of photoexcited carriers in coupled quantum wells around the Mott transition. We find that the diffusion of unbound electrons and holes is ambipolar and is characterized by a large diffusion coefficient, similar to that found in p-i-n junctions. Correlation effects in the excitonic phase are found to significantly suppress the carriers' diffusion. We show that this difference in diffusion properties gives rise to the appearance of a photoluminescence ring pattern around the excitation spot at the Mott transition.
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http://dx.doi.org/10.1103/PhysRevLett.101.257402 | DOI Listing |
Adv Sci (Weinh)
January 2025
Key Laboratory of the Ministry of Education for Advanced Catalysis Materials, Department of Chemistry, Zhejiang Normal University, Yingbin Road No.688, Jinhua, 321004, P. R. China.
Polycyclic multiple resonance (MR) molecules reveal narrowband emission, making them very promising emitters for high color purity display. Nevertheless, they still have challenges such as aggregation-induced emission quenching and spectral broadening. Overcoming these obstacles requires an in-depth understanding of the correlations among the alterations in their geometries, packing structures, and molecular vibrations and their corresponding changes in their photoluminescence (PL) properties.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
Department of Chemistry, University of Basel, St. Johanns-Ring 19, 4056 Basel, Switzerland.
Iridium is used in commercial light-emitting devices and in photocatalysis but is among the rarest stable chemical elements. Therefore, replacing iridium(III) in photoactive molecular complexes with abundant metals is of great interest. First-row transition metals generally tend to yield poorer luminescence behavior, and it remains difficult to obtain excited states with redox properties that exceed those of noble-metal-based photocatalysts.
View Article and Find Full Text PDFChemistry
January 2025
The University of Electro-Communications: Denki Tsushin Daigaku, Department of Engineering Science, JAPAN.
(6,5)-enriched single-walled carbon nanotubes (SWCNTs) were reductively arylated using sodium naphthalenide and monosubstituted and disubstituted iodobenzene derivatives to control their photoluminescence (PL) properties. In the reactions with substituted iodobenzenes, the degree of functionalization was influenced by the substituents on the aryl groups depending on their position, which allowed us to realize control of the PL intensity. The substituents at the 2-position and methyl groups at the 3,5-positions of the phenyl group respectively increased the E11** PL and E11* PL selectivity at ~1230 and ~1100 nm.
View Article and Find Full Text PDFOrg Lett
January 2025
Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
To experimentally investigate the impact of macrocyclic structures on the nonradiative decay rate constants () of thermally activated delayed fluorescence (TADF), a macrocyclic molecule L-ring and its analogue NL-ring were designed and synthesized. The photophysical measurements reveal their TADF characteristics, and the of the L-ring (4.19 × 10 s) is slower than that of the NL-ring (1.
View Article and Find Full Text PDFBeilstein J Org Chem
December 2024
Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS), CNRS-Université de Strasbourg (UMR 7504), F-67034 Strasbourg, France.
The high potential of non-covalent arene-fluoroarene intermolecular interactions in the design of liquid crystals lies in their ability to strongly promote self-assembly, improve the order and stability of the supramolecular mesophases, and enable tuneability of the optical and electronic properties, which can potentially be exploited for advanced applications in display technologies, photonic devices, sensors, and organic electronics. We recently successfully reported the straightforward synthesis of several mesogens containing four lateral aliphatic chains and derived from the classical triphenylene core self-assembling in columnar mesophases based on this paradigm. These mesogenic compounds were simply obtained in good yields by the nucleophilic substitution (SFAr) of various types of commercially available fluoroarenes with the electrophilic organolithium derivatives 2,2'-dilithio-4,4',5,5'-tetraalkoxy-1,1'-biphenyl (2Li- ).
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