Improved organic-inorganic/graphene hybrid composite as encapsulant for white LEDs: Role of graphene, titanium (IV) isopropoxide and diphenylsilanediol

Author(s) Reddy, M.; Chang, C.J.; Lai, C.F.; Su, M.J.; Tsai, M.H.
Journal Composites Science and Technology
Date Published 09/2018
Abstract We report a graphene embedded organic-inorganic hybrid (O-I hybrid) composites that can be utilized as robust encapsulants for white light emitting diodes (WLEDs). The effect of graphene and monomers on the thermal resistance, refractive index (RI), transparency, thermal conductivity, and thermal aging stability of the encapsulant were studied. This study has explicitly unveiled that the embedded graphene played a multifunctional role in producing a high-performance encapsulant. Compared with graphene free O-I hybrid encapsulant, RI, thermal conductivity and heat dissipation ability of the graphene embedded encapsulants were significantly improved. After continuous operation for 10 days, the color rendering index (Ra) of WLED with graphene embedded encapsulants changed from 89.5 to 89.2 (driving current 100 mA), while the correlated color temperature (CCT) altered from 4535 to 4546. Its luminous efficiency changed from 82.9 to 81.2 lm/W. The WLEDs with graphene embedded O-I hybrid encapsulant exhibited long-term stability. This work has paved the way for rational design and assembly of graphene embedded composites as robust materials for various requirements of WLED applications.
DOI 10.1016/j.compscitech.2018.06.017
ISSN 0266-3538
Citation Composites Science and Technology. 2018;165:95105.

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