Towards white light emission in Dy3+/Sm3+ co-doped niobio silicate glasses via adjusting doping concentration and excitation wavelength for w-LED applications.

The commercial LED has the disadvantages of low thermal stability and poor luminous quality at high temperature due to the organic resin encapsulation phosphor, and luminous glass is one of the effective ways to solve this problem. A series of niobium silicate (SiO 2 –Nb 2 O 5 –Na 2 O–K 2 O–Dy 2 O 3 –Sm 2 O 3 , labeled as SNNKDS) luminous glasses have been obtained by melt quenching method. The results of differential thermal analysis prove the existence of high thermal stability. The infrared spectrum, Raman spectrum and the calculation of physical parameters reveal the excellent thermal stability and stable structure of the prepared glass. The optical properties of luminescent glass have been studied in detail, the energy transfer from Dy3+ ions to Sm3+ ions has been observed, the Dy3+/Sm3+ co-doping glasses can achieve warm white light emission by changing the excitation wavelength and the doping amount of Sm3+. The variable temperature emission spectrum of SNNK:0.8D0.4 S is analyzed. At 423 K, the comprehensive emission intensity is 79.91 % of that at room temperature, the Δ C value of colorimetric shift at 473 K is 2.1 × 10−2. The warm white light output with excellent correlated color temperature (3746 K) has been achieved using glass samples encapsulated with 395 nm LED chip. The analysis shows that Dy3+/Sm3+ co-doped niobium silicate glasses can be regarded as a candidate for the w -LED applications. [ABSTRACT FROM AUTHOR]