Full color white light, temperature self‐monitor, and thermochromatic effect of Cu⁺ and Tm³⁺ codoped germanate glasses

Abstract

As one of the most promising solid state lighting (SSL) sources, white-light emitting diodes (w-LEDs) were greatly popularized during most recent decade, and began to replace gradually conventional incandescent and fluorescent lamps in the marketplace due to their serving longevity, environmental friendliness, high efficiency, excellent sturdiness and so on. 1-5 At present, two mainstream methods to fabricate w-LEDs are wieldy adopted: one is the combination of yellow-emitting YAG:Ce 3+ phosphor with InGaN blue-emitting chip; another is coating the red, green, and blue (tricolor phosphors) emitting phosphors on near-ultraviolet (NUV) chip. 6-8 However, the former suffers from low color rendering index (CRI) and poor correlated color temperature (CCT) due to the lack of red components in its spectrum. The latter

Net Optical Gain Coefficients of Cu+ and Tm3+ Single-Doped and Co-Doped Germanate Glasses

“…As mentioned in the introduction, in a previous study [ 12 ], it was found that Cu + -doped germanate glass can generate a super-broadband emission which implies potential application for visible tunable lasers. In order to examine the feasibility of the broadband tunable laser operation of the studied glass, optical gain characterization of the Cu + -doped germanate glasses was performed using the setup shown in Figure 1 .…”

“…The copper ion, in particular, is characterized by a partially filled d shell and possesses outstanding fluorescence properties due to the presence of multiple valence and coordination states [ 11 ]. In our previous work, the fluorescence properties of Cu + - and Tm 3+ -doped germanate glasses were investigated, with a broadband emission ranging from 400 to 700 nm in the studied glasses observed, which could be useful for the implementation of white light sources [ 12 ]. The previously obtained results prompted us to consider that the Cu + - and Tm 3+ -doped germanate glasses may also possess broadband optical gain characteristics, with potential application prospects in visible CW broadband lasers.…”

Self‐reduction and enhanced luminescence in transparent Mn2+‐doped mullite glass‐ceramics derived from EMT‐type zeolite

“…Phosphor‐converted white light‐emitting diodes (WLEDs), as the new generation lighting sources, have gathered much attentions and been widely applied in our daily lives 1–3 . The commercial WLED consists of a blue chip and YAG:Ce phosphors in organic resin or silicone.…”

“…Phosphor-converted white light-emitting diodes (WLEDs), as the new generation lighting sources, have gathered much attentions and been widely applied in our daily lives. [1][2][3] The commercial WLED consists of a blue chip and YAG:Ce phosphors in organic resin or silicone. However, the organic light converter inevitably becomes mature and yellow due to the low stability, ultimately resulting in the degradation of luminous intensity and chromaticity shift of WLED.…”