Green and red phosphor for LED backlight in wide color gamut LCD

Yunpeng Zhang¹，Lin Luo²，Guantong Chen²，Yuanhong Liu²，Ronghui Liu²，Xiaochun Chen¹

1. Beijing University of Chemical Technology2. National Engineering Research Center for Rare Earth Materials,General Research Institute for Nonferrous Metals,Grirem Advanced Materials Co.,Ltd.

摘 要：Wide color gamut（WCG） backlight for liquid crystal display（LCD） utilizing white light-emitting diodes（LED） has attracted considerable attention for their high efficiency and color reduction.In this review,recent developments in crystal structure,luminescence and applications of phosphors for wide color gamut LED backlight are introduced.As novel red phosphors,Mn⁴⁺activate fluoride and aluminate phosphors are advanced in quantum efficiency,thermal quenching and color saturation for their characteristic spectrum with broad excitation band and linear emission.The crystal structure and fluorescence properties of Mn⁴⁺doped fluosilicate,fluorogermanate,fluotitanate,as well as Sr₄ Al₁₄O₂₅,CaAl₁₂O₁₉ and BaMgAl₁₀O₁₇ phosphors are discussed in detail.A serial of narrow-band red-emitting Eu²⁺,Eu³⁺and Pr³⁺-doped nitride silicates and molybdate phosphors are also introduced.Rare-earth-doped oxynitride and silicate green-emitting phosphors have attracted more and more attention because of the wide excitation,narrow emission,high quenching temperature,high quantum efficiency,such as β-sialon:Eu²⁺,Ba₃Si₆O₁₂N₂:Eu²⁺,MSi₂O₂N₂:Eu²⁺（M=Ca,Sr,Ba）,y-AlON:Mn²⁺and Ca₃Sc₂Si₃O₁₂:Ce³⁺.All above phosphors demonstrate their adaptability in wide color gamut LCD display.Especially for Mn⁴⁺doped fluosilicate red phosphor and β-sialon:Eu²⁺green phosphor.To achieve an ultra-high color gamut in white LED backlight and against the OLED,innovative narrow-band-emission red and green phosphor materials with independent intellectual property rights are continuously pursed.

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