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.

Zirconia/phenylsiloxane nano-composite for LED encapsulation with high and stable light extraction efficiency

“…A lot of efforts have been made to increase the RI of silicone materials [3][4][5][6] and their gas barrier properties [7][8][9][10][11] to enhance the light extraction efficiency (LEE) value and stability.…”

A Novel Liquid Packaging Structure of Deep-Ultraviolet Light-Emitting Diodes to Enhance the Light-Extraction Efficiency

“…On the other hand, the mainstream design of DUV-LED packages uses quartz glass as the cover without an encapsulation material inside the cavity [9]. This kind of package structure reduces the light extraction severely and limits the optical performance of DUV-LEDs [10,11]. To ameliorate these drawbacks, some DUV transparency encapsulation materials have been proposed for the DUV-LED package structure [12][13][14].…”

UV Curable Formulations for UV-C LEDs

“…On the other hand, there are a few reports on the application of UV-C LEDs, which emit lights below 300 nm, for sensors [9,10] and UV LED encapsulant [11]. To the best of our knowledge, there are no comprehensive studies of the formulations for UV-C LEDs which are applicable to practical use.…”