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Tunable Direct-White of Lanthanum Aluminate Phosphor for LED Via Valence State-Controllable Means

Author: MaoZhiYong
Tutor: WangDaJian
School: Tianjin University of Technology
Course: Condensed Matter Physics
Keywords: Direct White Fluorescent material Single matrix Bond Valence Theory
CLC: O482.31
Type: Master's thesis
Year: 2010
Downloads: 71
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Abstract


In the field of lighting and display, mostly based on artificial white light technology trichromatic color theory, the use of multi-component mixture of fluorescent materials convert light into white light mode. Panchromatic emission using a single component, namely, direct fluorescent material white mode is an innovative program, developed in recent years become a hot topic of race. This dissertation exploring a single lanthanum aluminate matrix, based on co-variation characteristic emission of Eu implement a new model of white light, the realization of an effective quality white light modulation. The main results of the work include the following four aspects: 1. Studied Eu 3 single doped LaAlO 3 red fluorescent material emitting properties. By examining the Eu 3 in the matrix of transition emission behavior and found that changing the Eu 3 doping concentration of luminescent centers, can strengthen the cross-relaxation between the luminescent center, inhibiting Eu 3 of the high-level emission, which can effectively improve the color purity of red light. 2 presents a new direct white mode, that is in the UV / near-ultraviolet excitation, the control based on a direct valence white LaAlO 3-δ : Eu fluorescent material, mixed valence Eu in characteristic emission of the matrix mixture to achieve a direct white light. In particular, that the green peak at 515 nm emission on white chromaticity modulation has an important role, found in the Eu 2 and Eu 3 of 5D2-assisted energy transfer, Eu 3 of the 5D2 → 7F2 transition emission is enhanced, thus realizing the 515 nm green emission. 3 examines the LaAlO 3-δ : Eu phosphor direct white light color control method comprises adjusting preparation of doped charge compensation of doped alkaline earth metal ions, such as Mn-doped. Focused analysis of Sr ions and Mn ions doped samples of light and color control and regulation mechanism. Through appropriate co-doped Sr or Mn ions, you can get one that takes a white CRI and color temperature. Regulation in Sr samples, O vacancy caused the emergence of Eu 2 of 5d state weight decreased resulting in Eu 2 and 5D2 energy transfer relationship between light and color enhancement is regulated the essence; regulation in Mn samples, it is directly through the Eu 2 and Mn 2 energy transfer between the light color changing relationship to achieve regulation. 4 Try using theoretical analysis of the bond valence valence state of Eu anomaly phenomena mechanism problem. That the bond valence theory applies to include the research system, including the rare earth ions in the matrix and the matrix Sites of replacing different valence Eu ions determine the stability. The dissertation on Eu valence state control and its matrix structure - the relationship between the light-emitting properties of research on the understanding of basic laws of optics have made scientific significance, research lanthanum aluminate white material directly in the UV / near UV-based white LED solid-state lighting have potential application value.

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CLC: > Mathematical sciences and chemical > Physics > Solid State Physics > Solid nature of the > Optical Properties > Luminescence
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