Luminescence of Eu[sup 2+] in Calcium Thiogallate

Abstract

Luminescence, decay, and thermal quenching under photonic excitation of CaGa2S4:Eu2+ mono and polycrystals have been measured. For excitation into the lower 5d states, thermal quenching starts above 350 K, which makes this material appropriate for use as a yellow phosphor under excitation by blue-emitting diodes. Thermoluminescence after 337.1 nm irradiation is explained by photoionization of Eu2+ ions. © 2002 The Electrochemical Society. All rights reserved.

Research challenges to ultra‐efficient inorganic solid‐state lighting

“…The values of CRI reported in this article are those of the general color rendering index (R a ). 7 In general, the higher the CRI, the lower the possible luminous efficacy. This is because the human visual response is not flat, but peaks at 555 nm.…”

“…In the general family of ternary sulfides M IIA M III 2 S 4 , the spectral position of Eu 2+ emission is a strong function of the crystal environment [7,33], shifting from blue-green (493 nm) to green (535 nm) to yellow (565 nm) with decreasing M II cation size (Ba, Sr, Ca), respectively, and with increasing M III cation size (Al, Ga, In). The green emission from the thiogallate SrGa 2 S 4 :Eu 2+ has a FWHM of 50 nm and a quantum efficiency of ∼ 80%.…”

Cathodoluminescence and Longevity Properties of Potential Sr1-xMxGa2S4:Eu (M = Ba or Ca) Green Phosphors for Field Emission Displays

“…[3][4][5][6][7] These reports indicated that Eu or Ce doped thiogallate phosphors exhibit excellent intrinsic efficiency, color purity, and current saturation behavior. Recent studies have also shown that the luminescence efficiencies of SrGa 2 S 4 :Eu and CaGa 2 S 4 :Eu are little affected by thermal quenching, [8][9][10] and have confirmed that SrGa 2 S 4 :Eu and CaGa 2 S 4 :Eu are suitable phosphors for lighting and display devices, especially for applications where heat effects are expected. However, the operational voltage requirements of FEDs have changed from low voltages (< 2 kV) to moderate voltages (2-10 kV), because carbon nanotube (CNT)-FEDs use higher voltage e-beams than Spindt-type FEDs in order to obtain greater brightness and longer lifetimes.…”

Термостимулированная люминесценция кристалла Ca(Al-=SUB=-x-=/SUB=-Ga-=SUB=-1-x-=/SUB=-)-=SUB=-2-=/SUB=-S-=SUB=-4-=/SUB=-:Eu-=SUP=-2+-=/SUP=-

“…44296.16340 Легированный редкоземельными элементами (РЗЭ) тиогаллат каль-ция (CaGa 2 S 4 ) является перспективным материалом в оптоэлектронике и фотонике [1]. Максимальная энергия фононов и хорошие оптические свойства позволяют получать высокоэффективные люминофоры, а элек-тропроводность бывает пригодна для создания электролюминесцентных дисплеев [2][3][4] [5][6][7][8][9][10]. CaGa 2 S 4 с примесью эрбия дает фотолюминесцен-цию на длине волны 1554 nm, что подходит для применения его в телекоммуникации [11].…”