Results 191 to 200 of about 541,582 (315)

Exciton Radiative Lifetimes in Hexagonal Diamond Ge and SixGe1–x Alloys

open access: yesAdvanced Optical Materials, EarlyView.
Strong room‐temperature photoluminescence reported in hexagonal Ge conflicts with theory predicting a nearly dark band edge. First‐principles calculations of excitonic radiative lifetimes fill a key gap in this debate, showing that pristine hexagonal Ge remains intrinsically weakly emissive, while Si alloying only modestly shortens the lifetime and ...
Michele Re Fiorentin   +2 more
wiley   +1 more source

On‐Chip Saturated Absorption of CO2 in a Silicon‐on‐Sapphire Waveguide

open access: yesAdvanced Optical Materials, EarlyView.
We demonstrate the first saturated absorption of a molecular gas on a planar photonic chip. By coupling carbon dioxide with the tightly confined light of a silicon‐on‐sapphire waveguide, we achieve optical saturation using only milliwatt powers. This breakthrough provides a practical, low‐power foundation for creating ultra‐compact mid‐infrared ...
Shahar Edelstein   +2 more
wiley   +1 more source

Exploring the Synergy of Combining BINAP and tCzBN Motifs Within Multi‐Resonant TADF Emitters to Enhance OLED Performance

open access: yesAdvanced Optical Materials, EarlyView.
This work presents two MR‐TADF emitters, BINAP‐BN1 and BINAP‐BN2, based on a BINAP core and differing numbers of tCzBN units. Both emitters show similar solution photophysics, but distinct behavior in doped films, where BINAP‐BN1 exhibits higher photoluminescence quantum yield and suppressed aggregation‐induced emission broadening compared to BINAP‐BN2.
John Marques dos Santos   +8 more
wiley   +1 more source

Mitigating Efficiency Roll‐Off in Phosphor‐Sensitized Fluorescence OLEDs via Molecular Polarity‐Based Benzofuropyridine Host Engineering

open access: yesAdvanced Optical Materials, EarlyView.
Positional isomerism in dibenzofuran‐based n‐type hosts modulates molecular polarity, charge‐transport balance, and emissive‐layer packing. The higher‐polarity BFPDB‐2 host facilitates efficient energy funneling, reduced aggregation, and preferential dipole orientation, leading to phosphor‐sensitized fluorescence OLEDs with enhanced external quantum ...
Nargis Ali   +3 more
wiley   +1 more source

Direct Measurement of the Singlet Lifetime and Photoexcitation Behavior of the Boron Vacancy Center in Hexagonal Boron Nitride

open access: yesAdvanced Optical Materials, EarlyView.
Negatively charged boron vacancy defects in hexagonal boron nitride promise near‐surface quantum sensing, but their internal spin transition rates are only partly understood. This work directly measures the defect's singlet‐state lifetime, 15(3) ns, using a nanosecond rise‐time dual‐pulse photoluminescence‐recovery method, and shows that high laser ...
Richard A. Escalante   +11 more
wiley   +1 more source

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