Phosphor‐in‐Silica‐Glass: Filling the Gap between Low‐ and High‐Brightness Solid‐State Lightings

Abstract

High‐brightness phosphor‐converted solid‐state light (SSL) sources based on blue light‐emitting diodes (LEDs) or laser diodes (LDs) will enable versatile optical applications other than general illumination. However, luminescence ceramics/crystals are too expensive for widespread use, while phosphor‐in‐glass converters suffer from low conversion efficiency at high‐power‐density excitation and poor chemical and thermal stabilities of low‐melting glasses. Herein, an ultrathin interface (<50 nm) is reported in Lu3Al5O12:Ce3+ phosphor‐in‐silica‐glass (LuAG:Ce‐PiSG) despite being sintered at 1250 °C, endowing them with high internal quantum efficiency (>95%) and excellent stabilities. Combined experimental results and first‐principles calculations reveal that the large formation energy of SiAl point defects makes the undesired interfacial reaction between aluminate garnets and silica glass intrinsically suppressed. Phosphor‐converted LEDs/LDs fabricated by LuAG:Ce‐PiSG exhibit high luminous efficiency (195 lm W−1 @ 20 mA) and high brightness (1914 lm @ 13.4 W mm−2), approaching the performances of their ceramic counterparts. The results not only provide a way to balance the brightness and the price for SSL sources but also unleash the potential of silica glass as an inorganic matrix for emerging optical applications.

Ultrahigh Power Density LuAG:Ce Green Converters For High‐Luminance Laser‐Driven Solid State Lighting

“…As shown in Figure a, the photoluminescence excitation (PLE) of prepared PiG and raw phosphor spectrum are composed of two emission peak bands at 350 and 450 nm, corresponding to the 4f→5d 1 and 4f→ 5d 2 valence band transitions of Ce 3+ , respectively. [ 38 ] The energy diagram of the 4f ‐ 5d energy level transition processes of the Ce 3+ are plotted in Figure 2b. [ 39 ] It is noteworthy that the LuAG:Ce‐PiG PL spectrum has the same emission peak at 520 nm, which is due to the de‐excitation process of the 5d 1 →4f transition.…”

CaAl2Si2O8:Dy3+, Eu3+: synthesis, luminescence properties, energy transfer, and tunable emission

“…If not, I 2 decreases with adding of z owing to the CQ of Eu 3+ ions. The R c value was calculated to be B13.9 Å by using eqn (2). Due to a spectral overlap between the PLE spectrum of Eu 3+ and the PL spectrum of Dy 3+ , the radiation reabsorption is the main type of interaction mechanism in CaAl 2 Si 2 O 8 :Dy 3+ , Eu 3+ with the excitation at 394 nm.…”

“…The luminescent materials based on rare earth (RE) ions have remarkable luminescence characteristics and play a very important role in many fields, such as display, solid-state lighting, optical thermometers, solar cells, lasers, radiation detection, white light-emitting diodes (LEDs), and temperature thermometry. [1][2][3][4][5] The trivalent rare-earth (RE 3+ ) ions have numerous energy levels and show narrow emission bands with extremely sharp peaks. 6 Among the RE 3+ ions, Dy 3+ and Eu 3+ ions are usually considered important activators.…”

Rapid synthesis of phosphor-glass composites in seconds based on particle self-stabilization

“…For example, some reports utilize low-sintering temperature ceramics (CaF 2 14 and hydroxyapatite 18 ) and low-melting temperature glass (tellurite 19 , 20 and phosphate glasses 21 , 22 ) as matrices to reduce the synthesis temperature and rely on hot isostatic pressing 23 , gas pressure sintering 24 , and spark plasma sintering technology 25 to suppress interface reactions. Moreover, Qiu et al discussed the intrinsic inhibition of interfacial reactions in PGC using silica glass instead of multi-component glass as the matrix 13 , 26 . Across all reported phosphor-glass/ceramic composites, a conspicuous disadvantage in regard to their synthetic procedure is the considerable time requirements necessary to form bulk composites.…”