Spectroscopic and crystal field analysis of absorption and photoluminescence properties of red phosphor CaAl12O19:Mn4+ modified by MgO

Luminescent properties of La2LiTaO6:Mn4+ and its application as red emission LEDs phosphor

“…enhancing the emission intensity of phosphor were also observed for Mn 4? doped CaAl 12 O 19 [28][29][30]. For La 2 LiTaO 6 :Mn 0.003 4?…”

A novel red phosphor Na+, Mn4+ co-doped Sr4Al14O25 for warm white light emitting diodes

“…A conventional W-LED using Y 3 A l5 O 12 :Ce 3þ (YAG:Ce 3þ ) phosphors excited by an InGaN blue LED chip has a low color rendering index (color rendering index <85) due to the lack of a red component in phosphors [2e4], which gives "cool" -white light. Therefore, in order to generate the white light with the warm perception similar to incandescent light, one of the best strategies is to mix a high efficient red phosphor with strong blue absorption into YAG: Ce [5]. Another alternative method is to coat an ultraviolet (UV) chip with red/green/blue (RGB) tricolor phosphors [6].…”

“…The red phosphors doped with rare earth ions, such as Eu 2þ , Eu 3þ , Ce 3þ and Sm 3þ are commonly used for conventional lighting [7e10], but it is well known that most of rare earth ions are very expensive [4,11]. At the same time, for Eu 3þ and Sm 3þ -doped red phosphors, the sharp absorption peaks in UV and blue region limit their application in current white LEDs [5]. Therefore, considerable efforts have been devoted to the development of the non-rareearth-based phosphors for exercise in W-LEDs [2,6].…”

Luminescent properties of Na3Gd1−xEux(PO4)2 and energy transfer in these phosphors

“…Today, the WLED market is dominated by phosphor-converted WLEDs normally comprising a 450-470 nm blue InGaN LED chip covered by a yellow phosphor, which is usually made of YAG:Ce 3+ [7][8][9][10][11][12]. However, phosphorconverted WLEDs made by means of blue-LED + yellow phosphor suffer from the drawbacks such as halo effect due to the different emission characteristics of the LEDs (directional) and the phosphors (isotropic) [13], low color rendering index (CRI) and high color temperature caused by lack of red component in the spectra [2,7,[10][11][12]14,15]. White light can also be produced by another method, i.e., using a near ultraviolet (NUV) LED (370-410 nm) to stimulate the mixture of red, green and blue (RGB) phosphors [1][2][3]7,10].…”