Luminescent properties of near UV excitable Ba₂ZnS₃ : Mn red emitting phosphor blend for white LED and display applications

Abstract

A bright red colour emitting Mn doped Ba2ZnS3 phosphor was prepared by an ecologically acceptable carbothermal reduction method without an inert gas or hazardous gas (H2S) environment. The phosphor can be excited with UV wavelength radiation to realize emission in the visible range. X-ray diffraction studies confirm an orthorhombic structure with phase group, pnam. The photoluminescence (PL) emission spectrum shows a broad band with emission maximum at 625 nm under the host excitation of 358 nm, which lies in the near UV region. The concentration of Mn was varied from 0.0025 to 0.20 mole with respect to Zn and the optimum PL emission intensity was obtained at the concentration of 0.01 mole of Mn. The CIE (Commission Internationale de l'Eclairage) colour coordinates measurement (x = 0.654 and y = 0.321) shows that the primary emission is in the red region. The triband phosphors blend containing Sr5(PO4)3Cl : Eu2+ (blue), ZnS : Cu,Al (green) and Ba2ZnS3 : Mn (red) shows white light emission under 365 nm excitation having CIE chromaticity (x = 0.292 and y = 0.251). Since phosphor excitation lies in the near UV excitable region, giving a bright red emission, it can be used for applications in near UV phosphor converted white LED lighting and display devices.

Preparation and photoluminescence properties of Mn2+-activated M2Si5N8 (M=Ca, Sr, Ba) phosphors

“…The half-width for the single narrow emission band of M 2 Si 5 N 8 :Mn 2+ phosphors is about 60 nm for M=Sr and Ba, and 70 nm for M=Ca, which resembles with the literature values, e.g. about 70 nm for Zn 3 (PO 4 ) 2 :Mn 2+ [29], 60 nm for Ba 2 ZnS 3 :Mn 2+ [20][21][22] and 40 nm for Zn 2 SiO 4 :Mn 2+ [30]. This half-width is significantly smaller than that of red Eu 2+ emission (100 nm) in M 2 Si 5 N 8 host lattices [4].…”

“…Thus, by the color mixing the white light was generated [16][17][18][19]. Recently, a new kind of Mn 2+ -doped LED conversion phosphor has been discovered, namely Ba 2 ZnS 3 :Mn 2+ [20][21][22]. This phosphor shows a broad emission band with peak center at about 625 nm under host excitation of 358 nm.…”

“…This phosphor shows a broad emission band with peak center at about 625 nm under host excitation of 358 nm. In combination with some other phosphors, white light was also generated [22]. The Mn 2+ ion usually gives a narrow band emission.…”

Concentration effect of cerium in (Y0.9−xGd0.1Cex)2SiO5 blue phosphor

“…For these reason, energy transfers (Ce2 → Ce1) between the two independent Ce 3+ ions in the Y1 and Y2 sites increase with the x-value, to cause PL red-shift. The similar phenomena have been reported on Eu 2+ -and Mn 2+ -doped phosphors, in their f-d and d-d type transitions, respectively [19][20][21][22].…”

Hydrothermal synthesis of transition-metal sulfide dendrites or microspheres with functional imidazolium salt

“…In recent years, the synthesis and properties characterization of nanometersized transition-metal semiconductors with novel controlled shape and structure have been attracting an increasing interest owing to their excellent physical and chemical properties [1][2][3] and their potential applications on photo-electronic transition devices [4][5][6][7][8][9]. However, considerable efforts have been devoted to the preparation of transition-metal sulfide semiconductors [10][11][12].…”