ceramic phosphor requires a long period of high-temperature sintering. In addition, the ceramic phosphor typically used in white lighting has an intrinsic limit for the dissipation of heat due to its low thermal conductivity. [10][11][12][13][14] Here, we introduce a thermally robust phosphor-aluminum (Al) composite fused with low-melting glass, which is processed by low-temperature sintering for a relatively short time. We achieve a thermal conductivity of 31.6 W m −1 K −1 in the composite, which is twenty times that of the reference sample (1.5 W m −1 K −1 ). Consequently, our composite exhibits excellent thermal stability in luminous flux and chromaticity under a 4 W blue laser diode (LD). In addition, we found that electric power can be produced in the composite during lighting by coupling to a thermoelectric (TE) module. Furthermore, our results show that the heat flow of the phosphor can be controlled through a cost-effective method. We anticipate that our report will be a starting point for further research in the composite-material design for energy recycling with high-power white lighting.A phosphor is a substance that exhibits luminescence caused by the absorption of external energy. In the simplest architecture of the solid-state white lighting, the phosphor is combined with blue light-emitting devices based on semiconductors. There are various types of phosphors that have different emission characteristics when combined with a blue-light source. [7] The quality of white light is dependent on the use of a phosphor that produces a broad spectral range. The most common method for fabricating the phosphor layer is the use of an organic resin as a binding agent for cohesion between the phosphor particles. [10,15] However, the phosphor-resin structure is not suitable for application in high-power white lighting because of the low thermal conductivity of the resin (0.1-0.4 W m −1 K −1 ), which does not allow sufficient dissipation of the heat generated by the irradiation of the strong blue light, which in turn controls the efficiency and brightness of the white light. [16][17][18][19][20][21][22] The resulting heat accumulation degrades the performance of the phosphor and the resin, limiting the production of stable highpower white lighting. Therefore, a resin-free phosphor layer is an essential requirement for high-power white lighting.There are two ways of providing a resin-free phosphor layer: one is a monolithic polycrystalline or monocrystalline ceramic phosphor, and the other is a phosphor-glass composite. [9,11,12,[23][24][25][26][27] The former has a high thermal conductivity A state-of-the-art solid-state lighting (SSL) device comprises a blue lightemitting device covered with a yellow-emitting phosphor. In a high-power SSL device, thermal stability is an essential requirement for the phosphor because the phosphor is constantly irradiated with high-power blue light, which causes thermal degradation. In this work, a thermally robust phosphor-aluminum composite (PAC) fused with low-melting glass is in...

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Functionally graded materials (FGMs) are compositionally gradient materials. They can achieve the controlled distribution of the desired characteristics within the same bulk material. We describe a functionally graded (FG) metal-phosphor adapting the concept of the FGM; copper (Cu) is selected as a metal and Cu- and Cl-doped ZnS (ZnS:Cu,Cl) is selected as a phosphor and FG [Cu]-[ZnS:Cu,Cl] is fabricated by a very simple powder process. The FG [Cu]-[ZnS:Cu,Cl] reveals a dual-structured functional material composed of dense Cu and porous ZnS:Cu,Cl, which is completely combined through six graded mediating layers. The photoluminescence (PL) of FG [Cu]-[ZnS:Cu,Cl] is insensitive to temperature change. FG [Cu]-[ZnS:Cu,Cl] also exhibits diode characteristics and photo reactivity for 365 nm -UV light. Our FG metal-phosphor concept can pave the way to simplified manufacturing of low-cost and can be applied to various electronic devices.