Full-visible-spectrum emission with high color rendering index and low correlated color temperature enabled by a single-phased phosphor of α-Sr_2V_(1.98)P_(0.02)O_7: 0.5% Eu~(3+)

摘要

A single-phased warm white phosphor of alpha-Sr2V1.98P0.02O7: 0.5 % Eu3+ with low correlated color temperature (CCT) and high color rendering index (CRI) was synthesized by high temperature solid phase method. By changing the ratio of PO43- /VO43-, the emission intensity of VO43- and the energy transfer efficiency of VO43-- Eu3+ can be effectively tuned, and the full-spectrum warm white light emission of phosphors in the range of 400-700 nm can be realized. Moreover, the temperature-dependent emission spectra and thermal quenching properties were investigated in detail. On this basis, the WLED prototype devices were packaged with the synthesized phosphors alpha-Sr2V1.98P0.02O7: 0.5 % Eu3+ and 365 nm near-ultraviolet (NUV) chips and high-quality warm white light emission with CCT = 3188 K and CRI Ra = 93.5 were achieved. These findings provide new insights into exploring single-phased white phosphors for NUV-pumped warm w-LEDs with high CRI property and low CCT value.