Results 161 to 170 of about 7,192 (202)

Low-temperature photoluminescence upconversion in porous Si

Physical Review B, 2000
We report efficient low-temperature upconverted photoluminescence ~UPL! at resonant excitation of the porous Si photoluminescence band. The UPL has a linear dependence on the excitation intensity, quenches at elevated temperatures, and is absent in strongly oxidized porous Si and oxidized Si nanocrystals.
D. Kovalev, J. Diener, H. Heckler, G. Polisski, N. Künzner, F. Koch, Al. L. Efros, M. Rosen   +7 more
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Photoluminescence and upconversion optical properties of the CaS:Sm3+ nanocrystallites

Applied Physics Letters, 1998
The CaS:Sm3+  nanocrystallites are synthesized by the modified sol-gel technique. The grain size of the nanocrystallites is approximately 60 nm, which is determined by transmission electron microscopy, x-ray diffraction and UV-vis absorption spectrum. Compared to the CaS:Sm3+ macrocrystallites, the absorption and emission of the nanocrystallites have a
Chen, WJ, Gong, X, Wu, PF, Chan, WK
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Upconversion photoluminescence of Er3+ and Yb3+ codoped MoS2 powders

Journal of Luminescence, 2020
Abstract Er3+ and Yb3+ codoped MoS2 powders have been fabricated by hydrothermal synthesis. The impact of Er3+ and Yb3+ codoping on the structure, morphology, energy band structure and upconversion photoluminescence properties of samples have been studied by XRD, SEM, TEM, XPS and UPL.
Mengmeng Lun, Wanying Wu, Zhifeng Xing, Hanzhao Song, Yinzhen Wang, Wei Li, Benli Chu, Qinyu He   +7 more
openaire   +1 more source

Photoluminescence and upconversion on Ag/CdTe quantum dots

Optics & Laser Technology, 2014
Abstract Different sizes of aqueous CdTe QDs have been prepared by microwave via controlling the temperature and time of irradiation. To study the plasmonic effect on CdTe QDs, Silver NPs were prepared by using a chemical reduction method. Structure characterization of the nanocrystals (Ag NPs and CdTe QDs) was determined by transmission electron ...
A.E. Ragab, A.-S. Gadallah, M.B. Mohamed, I.M. Azzouz   +3 more
openaire   +1 more source

Photoluminescence in Gd2O3: Er3+, Yb3+ upconversion inverse opal

Journal of Physics and Chemistry of Solids, 2012
Abstract Photoluminescence properties of Gd 2 O 3 : Er 3+ , Yb 3+ upconversion inverse opal photonic crystals were investigated. The photoluminescence spectra of the inverse opal show strong dependence on upconversion emission intensity and the corresponding photonic band-gaps of the inverse opal.
Zhengwen Yang, Dong Yan, Hangjun Wu, Rongfei Wang, Zhiguo Song, Dacheng Zhou, Xue Yu, Yong Yang, Zhaoyi Yin, Lei Yan, Jianbei Qiu   +10 more
openaire   +1 more source

Epitaxial KNbO3:Yb3+,Er3+ nanopattern for enhanced upconversion photoluminescence

Journal of Alloys and Compounds, 2020
Abstract Nanopatterned epitaxial films of upconversion (UC) materials are desirable for various applications such as display lighting, waveguides, and optical imaging. In this study, we demonstrate that a nanopatterned epitaxial film of a UC material can be fabricated by combining a sol–gel process and nanoimprint lithography. An epitaxial KNbO3:Yb3+,
Heeyeon Park, Kyu-Tae Lee, Soon-Hong Kwon, In Hwan Ahn, Byunghoon Kim, Doo-Hyun Ko, Woong Kim   +6 more
openaire   +1 more source

Upconversion photoluminescence of CdS nanocrystals in polymeric film

Journal of Applied Physics, 2008
We report on nonlinear upconversion photoluminescence (PL) of CdS nanocrystals (NCs) embedded in a polymeric film. The CdS NCs of 2 nm radius are synthesized by an ion exchange method and highly concentrated in the two layers near the surfaces of a freestanding Nafion film.
He, J., Scholes, G.D., Qu, Y.L., Ji, W.
openaire   +1 more source

Improved multiphoton ultraviolet upconversion photoluminescence in ultrasmall core-shell nanocrystals

Optics Letters, 2014
Near-infrared to ultraviolet multiphoton upconversion photoluminescence in ultrasmall Tm3+/Yb3+-codoped CaF2 nanocrystals (∼6.7  nm in size) was observed and further significantly enhanced by growing an active shell of NaYF4:Yb3+. Owing to the active shell, the lanthanide emitters inside the core are effectively prevented from the surface quenchers ...
Lili, Tao, Bo, Zhou, Wei, Jin, Yang, Chai, Chun-Yin, Tang, Yuen H, Tsang   +5 more
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Two-photon upconversion photoluminescence in CsPbBr3 nanoplates

Applied Physics Letters
The utilization of solar energy by light conversion processes in both natural and artificial photosynthesis systems has become a pivotal means of sustaining a consistent power supply for our daily lives and production. In general, these reactions rely on the visible spectra region where the sun produces abundant energy according to the black body's ...
Yu Rong, Shuai Yuan, Jun Zhan, Xiao Huang, Jie Gao, Xiaowen Gao, Xinli Wang, Hao-Yi Wang, Xi-Cheng Ai   +8 more
openaire   +1 more source

Tip Enhancement of Upconversion Photoluminescence from Rare Earth Ion Doped Nanocrystals

ACS Nano, 2015
We present tip-enhanced upconversion photoluminescence (PL) images of Er(3+)- and Yb(3+)-doped NaYF4 nanocrystals on glass substrates with subdiffraction spatial resolution. Tip-sample distance dependent measurements clearly demonstrate the near-field origin of the image contrast.
Nina Mauser, Dawid Piatkowski, Tobia Mancabelli, Marcin Nyk, Sebastian Mackowski, Achim Hartschuh   +5 more
openaire   +2 more sources