A Low-temperature Emission Band from Dilute Solutions of Pure Chlorophyll a

Nature ◽  
1963 ◽  
Vol 199 (4898) ◽  
pp. 1097-1098 ◽  
Author(s):  
SEYMOUR STEVEN BRODY ◽  
S. B. BROYDE
Keyword(s):  
Low Temperature ◽  
Chlorophyll A ◽  
Emission Band ◽  
Dilute Solutions

STUDY OF NANOSTRUCTURES OF ZINC OXIDE SYNTHESIZED BY LOW-TEMPERATURE HYDROTHERMAL METHOD

2018 ◽  
Vol 20 (4) ◽  
pp. 209-217
Author(s):  
S.S. Kurbanov ◽  
Sh.Z. Urolov ◽  
Z.Sh. Shaymardanov ◽  
R.R. Jalolov
Keyword(s):  
Low Temperature ◽  
Hydrothermal Method ◽  
Emission Band ◽  
Free Exciton ◽  
Zno Nanorods ◽  
Growth Direction ◽  
Orange Emission ◽  
Yellow Orange ◽  
Violet Band ◽  
Vertically Aligned

Room temperature photoluminescence (PL) properties of vertically aligned and spindle-shaped, randomly oriented ZnO nanorods synthesized by using a low temperature hydrothermal method are studied. In air, the vertically aligned ZnO nanorods oriented mainly parallel to the luminescencerecording axis exhibited only one, very strong UV emission peak at 382 nm. This band is assigned to emission of free excitons. A new violet PL band near 400 nm arises with increasing angle between the nanorod growth direction and the luminescence-recording axis. The violet band also appears under UV illumination in vacuum and vanishes after exposure to air. The randomly oriented ZnO nanorods along with free exciton related PL band reveal a broad yellow-orange emission band around 590 nm. The violet band is attributed to Zn vacancy related defects or their complexes, while the yellow-orange emission band is ascribed to oxygen interstitial related defects.

Low temperature synthesis of CsPbI 3 sub-micrometer wires with tailored emission band for flexible X-ray phosphors applications

2017 ◽  
Vol 188 ◽  
pp. 454-459 ◽  
Author(s):  
Junqian Zhao ◽  
Huaina Yu ◽  
Shusheng Pan ◽  
Shang Zhou ◽  
Li Zhong ◽  
...  
Keyword(s):  
Low Temperature ◽  
Emission Band ◽  
Low Temperature Synthesis ◽  
Temperature Synthesis ◽  
X Ray

Color Centers in Magnesium Doped Polycrystalline Alumina

2001 ◽  
Vol 667 ◽  
Author(s):  
L. R. Brock ◽  
K. C. Mishra ◽  
Madis Raukas ◽  
Walter P. Lapatovich ◽  
George C. Wei
Keyword(s):  
Low Temperature ◽  
Emission Band ◽  
Emission Spectroscopy ◽  
Color Centers ◽  
Absorption Bands ◽  
Fluorescence Excitation ◽  
Polycrystalline Alumina ◽  
Zero Phonon Line ◽  
Related Defect ◽  
Single Crystal Sapphire

ABSTRACTWe have investigated color centers in MgO-doped polycrystalline alumina (PCA) using absorption, excitation, and emission spectroscopy. Most of the color centers that were reported in earlier studies of the crystalline material have been observed to be present in the polycrystalline material. The absorption spectral features observed in the PCA are attributed to various color centers; however, they are not sufficiently resolved to make unique assignments. Suitable combinations of excitation and emission spectroscopy and also measurements at low temperature were therefore used to identify most of the color centers in this material.Among the numerous color centers that we have identified in PCA are variations of electron centers including F, F+, F2+, F22+ and F+-Mg ((Vo•-MgAl')x). The most prominent oxygen vacancy related defect observed at room temperature was the F+-Mg center, with absorption bands located at 217 and 249 nm, and an emission band at 303 nm. This center can be thought of as being formed by association of an F+ center with a Mg defect. The single crystal sapphire samples containing no Mg show only F+ (Vo•) centers with 230 and 257 nm absorption bands, and a 328 nm emission band.Low temperature (22 K) fluorescence excitation measurements of PCA led to emission from F22+center at 467 nm. Additionally, there is evidence that the observed 368 nm emission band could be attributed to the zero-phonon line associated with the F2+center.

scholarly journals Free and self-trapped exciton emission in perovskite CsPbBr3 microcrystals

RSC Advances ◽  
2022 ◽  
Vol 12 (2) ◽  
pp. 1035-1042
Author(s):  
Fang Pan ◽  
Jinrui Li ◽  
Xiaoman Ma ◽  
Yang Nie ◽  
Beichen Liu ◽  
...  
Keyword(s):  
Low Temperature ◽  
Emission Band ◽  
Exciton Emission ◽  
Cvd Method

A broad STE emission band together with a FE emission was found at low temperature in a CsPbBr3 microcrystal sample prepared by CVD method.

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