Hybrid excitons, characterized by their strong oscillation strength and long lifetimes, hold great potential as information carriers in semiconductors. They offer promising applications in exciton-based devices and circuits. MoSe/WS heterostructures represent an ideal platform for studying hybrid excitons, but how to regulate the exciton lifetime has not yet been explored. In this study, layer hybridization is modulated by applying electric fields parallel or antiparallel to the dipole moment, enabling us to regulate the exciton lifetime from 1.36 to 4.60 ns. Furthermore, the time-resolved photoluminescence decay traces are measured at different excitation power. A hybrid exciton annihilation rate of 8.9 × 10 cm s is obtained by fitting. This work reveals the effects of electric fields and excitation power on the lifetime of hybrid excitons in MoSe/WS 1.5° moiré heterostructures, which play important roles in high photoluminescence quantum yield optoelectronic devices based on transition-metal dichalcogenides heterostructures.
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http://dx.doi.org/10.1002/advs.202403127 | DOI Listing |
Nanoscale
January 2025
4109 Newman & Wolfrom Laboratory, 100 W 18th Ave, Columbus, OH 43210, USA.
A variety of ZnCdS-based semiconductor nanoparticle heterostructures with extended exciton lifetimes were synthesized to enhance the efficacy of photocatalytic hydrogen production in water. Specifically, doped nanoparticles (NPs), as well as core/shell NPs with and without palladium and platinum co-catalysts, were solubilized into water using various methods to assess their efficacy for solar H fuel synthesis. The best results were obtained with low bandgap ZnCdS cores and ZnCdS/ZnS core/shell NPs with palladium co-catalysts.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2025
Ningbo Institute of Materials Technology and Engineering CAS: Chinese Academy of Sciences Ningbo Institute of Materials Technology and Engineering, Key Laboratory of Advanced Marine Materials, Ningbo Institute of Materials Technology and Engineering, CHINA.
High-temperature phosphorescence (HTP) materials have attracted considerable attention owing to their expanded application prospects, whereas they still suffer from severe deactivation in polar media, limiting their reliability and utility. Here, we present an efficient multivalent assembly strategy to achieve high-temperature liquid-phase phosphorescence (HTLP). The supramolecular assembly of multivalent modules leads to extremely robust hydrogen-bonding networks, which firmly immobilize the organic phosphors and protect triplet excitons from annihilation in high-temperature polar media, resulting in excellent HTLP emission.
View Article and Find Full Text PDFNanoscale
January 2025
The Canter for Photochemical Sciences and Department of Physics, Bowling Green State University, Bowling Green, Ohio 43403, USA.
Laser diodes based on solution-processed semiconductor quantum dots (QDs) present an economical and color-tunable alternative to traditional epitaxial lasers. However, their efficiency is significantly limited by non-radiative Auger recombination, a process that increases lasing thresholds and diminishes device longevity through excessive heat generation. Recent advancements indicate that these limitations can be mitigated by employing spherical quantum wells, or quantum shells (QSs), in place of conventional QDs.
View Article and Find Full Text PDFJ Phys Chem A
January 2025
Shandong Province Key Laboratory of Medical Physics and Image Processing Technology, School of Physics and Electronics, Shandong Normal University, Jinan 250014, China.
Organic room-temperature phosphorescence (RTP) emitters with long lifetimes, high exciton utilizations, and tunable emission properties show promising applications in organic light-emitting diodes (OLEDs) and biomedical fields. Their excited-state properties are highly related to single molecular structure, aggregation morphology, and external stimulus (such as hydrostatic pressure effect). To gain a deeper understanding and effectively regulate the key factors of luminescent efficiency and lifetime for RTP emitters, we employ the thermal vibration correlation function (TVCF) theory coupled with quantum mechanics/molecular mechanics (QM/MM) calculations to investigate the photophysical properties of three reported RTP crystals (Bp-OEt, Xan-OEt, and Xan-OMe) with elastic/plastic deformation.
View Article and Find Full Text PDFJ Phys Chem B
January 2025
OncoImmunin, Inc., 207A Perry Parkway, Suite 6, Gaithersburg, Maryland 20877, United States.
We have previously found that the presence of an H-type excitonic dimer formed by two fluorophores covalently bound to an oligonucleotide allows the delivery of such a polymer into live cells without inducing toxicity. We are now using time-resolved fluorescence measurements in solution to understand the molecular dynamics of an antisense probe and how pairing with complementary sense strands of various lengths and degrees of complementarity affects the antisense strand's properties. We report that a DNA strand composed of 30 residues and labeled with an H-type excitonic Cyanine-5/Cyanine-5 dimer shows a predominant 1.
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