Reinforced heat dissipation by simple graphene coating for phosphor-in-glass applied in high-power LED

A well dispersed graphene oxide sol was prepared by the improved Hummer method. The atomic force micrographs showed a monolayer structure and larger sheet area. Aiming at improving the poor heat dissipation ability of Phosphor-in-glass (PiG)for remote packaged LED, the reduced graphene oxide film was prepared by photoreduction that after the sol was coated on PiG. UV-Vis spectra showed that the degree of reduction of graphene oxide was related to the illumination time, while the reduced graphene film had high transmittance without affecting the luminescent properties of the fluorescent material. At the same time, the excellent thermal conductivity of the film significantly enhanced the cooling capacity of the PiG, which has a lower stable operating temperature and a higher luminous intensity under highpower excitation compared with the uncoated ones. Software simulation also showed similar results of heat dissipation. (C) 2018 Elsevier B.V. All rights reserved.