Results 131 to 140 of about 32,897 (303)

Ultrafast dynamics in InAs quantum dot and GaInNAs quantum well semiconductor heterostructures

open access: yes, 2007
The quantum confined Stark effect (QCSE) and ultrafast absorption dynamics near the bandedge have been investigated in p-i-n waveguides comprising quantum confined heterostructures grown on GaAs substrates, for emission at 1.3um.
Malins, David B
core  

Ultrafast transverse relaxation exchange NMR spectroscopy

open access: yes, 2022
Molecular exchange between different physical or chemical environments occurs due to either diffusion or chemical transformation. Nuclear magnetic resonance (NMR) spectroscopy provides a means of understanding the molecular exchange in a noninvasive way ...
Mankinen, O. (Otto)   +3 more
core  

Tuning Excitonic Properties and Charge Carrier Dynamics by Halide Alloying in Cs3Bi2(Br1−xIx)9 Semiconductors

open access: yesAdvanced Optical Materials, EarlyView.
This work studies the effect of halide alloying in Cs3Bi2(Br1−xIx)9 (0 ≤ x ≤ 1) semiconductors. The x = 0.6 shows the smallest bandgap, lowest exciton binding energy, and longest charge carrier lifetimes, showing promising properties for optoelectronic and photocatalytic applications.
He Zhao, Eline M. Hutter
wiley   +1 more source

Disorder‐Induced Extremely Low Thermal Conductivity of Graphite Fluoride

open access: yesAdvanced Science, EarlyView.
This article investigates the effect of fluorination on the thermal conductivity of graphite fluoride, demonstrating the relationship between structural modification and thermal conductivity in an extreme case. The record‐low through‐plane thermal conductivity measured in exfoliated graphite fluoride flakes was found to correlate with the wide ...
Wonsik Lee   +10 more
wiley   +1 more source

Ultrafast spectroscopy of semiconductors and semiconductor nanostructures

open access: yes, 1996
Ultrafast Spectroscopy of Semiconductors and Semiconductor Nanostructures Ultrafast spectroscopy of semiconductors is currently one of the most exciting areas of research in condensed-matter physics Remarkable recent progress in the generation of tunable
Shah, Jagdeep
core   +1 more source

Photonic Time Crystals and Time‐Varying Electromagnetic Metamatter: A New Direction for Ultrafast Tunable Photonic and Microwave Materials and Devices

open access: yesAdvanced Science, EarlyView.
Photonic time crystals (PTCs) are systems in which electromagnetic parameters are modulated periodically in time, producing momentum bandgaps via temporal scattering rather than spatial Bragg processes. This review examines the theoretical frameworks, modeling, and computational tools for time‐varying media, and summarizes experimental demonstrations ...
Ranjan Kumar Patel   +3 more
wiley   +1 more source

Energy‐Resolved Femtosecond Dynamics of Plasmon‐Induced Hole Injection at Au/GaN Heterointerfaces

open access: yesAdvanced Science, EarlyView.
We reveal the spectral signature of ultrafast nonthermal hot‐hole transfer at plasmonic heterointerfaces, which reshapes hot‐carrier relaxation dynamics and significantly enhances hydrogen evolution, providing a mechanistic basis for optimizing hot‐carrier utilization in photocatalysis.
Yuying Gao   +8 more
wiley   +1 more source

Polymorphic Superparaelectric Engineering Boosting Energy Storage Capacity in BaTiO3‐Based Ceramics

open access: yesAdvanced Science, EarlyView.
Herein, Ca2+ incorporation promotes the coexistence of CaTiO3‐/BaTiO3‐derived paraferroelectric states, stabilizing cubic‐orthorhombic‐tetragonal polymorphic superparaelectric phases. This minimizes polarization energy barriers, facilitating full polarization saturation without compromising efficiency.
Pan Liu   +9 more
wiley   +1 more source

A Triple‐Nanoparticle System for Controlled Graphene Nanosheet Stacking: Enabling K/Na‐Ion Battery Anodes with Ultra‐Fast Charging Exceeding Petroleum Vehicle Refueling

open access: yesAdvanced Science, EarlyView.
ABSTRACT Large‐ion (K, Na) battery systems mitigate uneven global lithium distribution, while their ability to attain recharge time shorter than refueling would remove the final barrier for secondary batteries to replace petroleum vehicles. However, their large‐ion chemistry makes ultra‐fast charging an even significant challenge.
Shukai Ding   +12 more
wiley   +1 more source

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