A novel green‐emitting luminescent materials with broad‐band emission for high‐quality warm white LED indoor lighting

Abstract

Following the rapid growth of lighting technology, and in order to satisfy the higher requirement of people for lighting, the high‐quality warm white lighting for indoors has stolen much limelight of researchers. Herein, a novel green phosphor Ce3+‐doped Ca2GdHf2(AlO4)3 with garnet structure which can be used for warm white LED was developed by solid‐state method. Under 410 nm light excitation, the phosphor exhibits broad emission spectrum from 450 to 700 nm with FWHM more than 120 nm, and it also owns high internal quantum efficiency of 83.6%. The energy transfer among the activators was identified according to the concentration quenching and decrease of decay time, which belongs to dipole‐dipole interaction. The calculated activation energy is about 0.255 eV, indicating the moderate thermal stability. The fabricated white LED device with low CCT (3807 K) and high CRI (Ra = 89.2) demonstrates its superiority and possibility of practical application in high‐quality warm white LED fields for indoor lighting fields.

Eu2+ activated NaBa3Si2O7F: A new efficient blue‐emitting luminescent material for solid‐state lighting and display

“…As expected, the decay time gradually decreases from 587.40 to 420.77 ns with increase of Eu 2+ concentration from 0.005 to 0.050. This phenomenon is attributed to the increasing probability of nonradiation transfer caused by the increasing energy transfer due to reduced distance between Eu 2+ 40,42 …”

“…This phenomenon is attributed to the increasing probability of nonradiation transfer caused by the increasing energy transfer due to reduced distance between Eu 2+ . 40,42…”

An efficient blue phosphor with high thermal stability for lighting and optical pressure sensor applications

“…Fig. 3(b) provides the decay curve of Eu 2+ doped NCMPO under 370 nm excitation and 463 nm monitoring, and the decay curve can be well fitted by the single exponential equation: 9,35…”

“…Although an efficient white light can be obtained in this way, the correlated color temperature (CCT) of the obtained white light is higher and the color rendering index (CRI) is lower due to the lack of the red light component, so it is difficult to meet the requirements of high quality lighting. [9][10][11] In order to obtain white light with a high CRI and low CCT, researchers increased the red light by co-mixing other ions, but this is usually accompanied by a decrease in luminous efficiency and thermal stability. Besides, some red phosphors, such as (Ca,Sr) AlSiN 3 :Eu 2+ , (Ca,Sr)Si 5 N 8 :Eu 2+ , etc., with a high luminescence efficiency have been widely used in pc-LEDs to increase the red light component.…”

Structure evolution and tunable magneto‐optical multifunctional property study of novel Ca18K3Sc1‐xSmx(PO4)14 phosphors

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The rare earth doped magneto-optical materials can be used to produce optical devices with various functions in intersect disciplines, such as isolators, magneto-optical switches, magneto-optical sensors, etc., which brings great convenience to people's lives and has received extensive attention in recent years. 1,2

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