title: Ultraviolet light stable and transparent sol-gel methyl siloxane hybrid material for UV light-emitting diode (UV LED) encapsulant.
abstract: An ultraviolet (UV) transparent and stable methyl-siloxane hybrid material was prepared by a facile sol-gel method. The transparency and stability of a UV-LED encapsulant is an important issue because it affects UV light extraction efficiency and long-term reliability. We introduced a novel concept for UV-LED encapsulation using a thermally curable oligosiloxane resin. The encapsulant was fabricated by a hydrosilylation of hydrogen-methyl oligosiloxane resin and vinyl-methyl siloxane resin, and showed a comparable transmittance to polydimethylsiloxane (PDMS) in the UVB (∼300 nm) region. Most remarkably, the methyl-siloxane hybrid materials exhibited long-term UV stability under light soaking in UVB (∼300 nm) for 1000 h.
authors.affiliation: Laboratory of Optical Materials and Coating (LOMC), Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST) , Daejeon 305-701, Republic of Korea.
authors.forename: Jun-Young
authors.initials: JY
authors.lastname: Bae
authors.forename: YongHo
authors.initials: Y
authors.lastname: Kim
authors.forename: HweaYoon
authors.initials: H
authors.lastname: Kim
authors.forename: YuBae
authors.initials: Y
authors.lastname: Kim
authors.forename: Jungho
authors.initials: J
authors.lastname: Jin
authors.forename: Byeong-Soo
authors.initials: BS
authors.lastname: Bae
keywords: UV LED encapsulant; UV transparency; hybrid materials; methyl siloxane; sol−gel