A Promising Energy-Saving and Environmental-Friendly Lighting Device: High CRI White LED with Phosphor Materials

Abstract

Two kinds of commercial LED phosphors (green phosphor LuAG:Ce3+ and red phosphor CaAlSiN3:Eu2+) with polymethyl methacrylate (PMMA) powders were mixed to prepare film phosphors with tunable emission peak in photoluminescence spectrum by flat vulcanizing machine under the temperature of 170 oC and pressure of 2 MPa. The physical phase, surface morphology, transmittance, luminescence spectra of samples were characterized by means of X-ray diffraction (XRD), Environmental scanning electron microscopy (ESEM), Ultraviolet-Visible (UV-Vis) spectrophotometry and Fluorescence spectrometer. The results show that the film phosphors phase was consistent with raw phosphors, phosphor particles were uniformly distributed, and fluorescence spectra with different proportions of phosphors in different position can be adjusted. Tested by HSP 3000 spectrum analyzer, the white LEDs fabricated by blue chip and composite film phosphor containing 5 wt% green phosphor and 1.5 wt.% red phosphor, which refers to the remote excitation technique, possessed color coordinate of (0.3715, 0.3280) and color rendering index (CRI) of 87 when it was driven at power of 36 V/140 mA, reaching the international advanced level.

A zero-dimensional hybrid copper(i) bromide single crystal with highly efficient green emission

“…Although they are more stable than inorganic copper halides, their highest PLQY is only 35.2%, much lower than the other green light materials such as (18-crown-6 )2 Na 2 (H 2 O) 3 Cu 4 I 6 (91.8%) 28 and inorganic phosphor LuAG:Ce 3+ (84.1%). 29 Currently, selecting suitable organic cations remains a challenge due to the absence of clear guidelines, and there is still a need to discover more new materials.…”