Abnormal co-doping effect on the red persistent luminescence SrS:Eu2+,RE3+ materials

Rapidly prepared SrS:Eu2+,RE3+ exhibits long red persistent luminescence independent of the rare earth co-dopant due to a high Schottky defect concentration.

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Understanding Persistent Luminescence: Rare-Earth- and Eu2+-doped Sr2MgSi2O7

Zeitschrift für Naturforschung B ◽

10.5560/znb.2014-3322 ◽

2014 ◽

Vol 69 (2) ◽

pp. 171-182 ◽

Cited By ~ 11

Author(s):

Mika Lastusaari ◽

Högne Jungner ◽

Aleksei Kotlov ◽

Taneli Laamanen ◽

Lucas C. V. Rodrigues ◽

...

Keyword(s):

Rare Earth ◽

Band Gap ◽

Charge Compensation ◽

Band Gap Energy ◽

Persistent Luminescence ◽

Excitation Spectra ◽

Co Doping ◽

The Individual ◽

Initial Intensity ◽

The Eu

Similar to many other Eu2+,RE3+-co-doped persistent luminescence materials, for Sr2MgSi2O7:Eu2+,RE3+ the initial intensity and duration of persistent luminescence was also found to depend critically on the rare-earth (RE) co-doping. An enhancement of 1 - 2 orders of magnitude in these properties could be obtained by Dy3+ co-doping whereas total quenching of persistent luminescence resulted from the use of Sm3+ and Yb3+. To solve this drastic disparity, the effects of the individual RE3+ ions were studied with thermoluminescence (TL) spectroscopy to derive information about the formation of traps storing the excitation energy. The charge compensation defects were concluded to be the origin of the complex TL glow curve structure. The tuning of the band gap of the Sr2MgSi2O7 host and especially the position of the bottom of the conduction band due to the Eu2+,RE3+ co-doping was measured with the synchrotron radiation vacuum UV (VUV) excitation spectra of the Eu2+ dopant. The model based on the evolution of the band gap energy with RE3+ co-doping was found to explain the intensity and duration of the persistent luminescence.

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SYSTHESIS AND OPTICAL PROPERTIES OF RARE EARTHS DOPED NANO-SEMICONDUCTORS AND THEIR APPLICATIONS

International Journal of Modern Physics B ◽

10.1142/s0217979202015297 ◽

2002 ◽

Vol 16 (28n29) ◽

pp. 4294-4301 ◽

Cited By ~ 2

Author(s):

XINWEI ZHAO ◽

SUSUMU HARAKO ◽

SHINRI NOGUCHI ◽

SHUJI KOMURO

Keyword(s):

Rare Earth ◽

Rare Earths ◽

Optical Transition ◽

Rare Earth Ions ◽

Electron Hole ◽

Transition Dynamics ◽

Time Resolved ◽

Co Doping ◽

Nanocrystalline Si ◽

The Rare Earth

Er and Yb have been doped into nanocrystalline Si and ZnO thin films. Sharp and intense photoluminescence (PL) lines related to intra-4f transitions in the rare earth ions were observed. The optical transition dynamics of the rare earth ions were investigated by time-resolved PL measurements. It was demonstrated that a nano-meter sizing of Si widened the energy bandgap and led to an increase of doping densities of the rare earths. It was also shown that the Er-related PL gave rise to different features under direct and indirect excitations indicating a strong interaction of electron-hole pairs in the host with 4f electrons in the rare earth ions. A co-doping effect of Yb and Er into nanocrystalline Si was presented also. Our results suggested a rare earth-rare earth coupling between the Yb 3+ ions and the Er 3+ ions, which transferred the energy from Yb to Er and enhanced the 1.54 μm PL of Er.

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