Silicone-containing adhesive layer formed by cyclic ring-opening polymerization and comprising amounts of an organic base and bonding a wavelength converting layer to a thickness of sapphire in a light-emitting diode (LED) apparatus. Methods enabling its uninhibited curing so as to achieve contaminant-free and debris-free adhesion between surfaces. LED apparatus designed and manufactured such that surfaces to be bonded together are prepared in a manner that facilitates use of high-refractive-index adhesives. A multi-step process involving two different concentrations of a catalyst is performed so as to fabricate highly-reliable, non-browning, and non-cracking high-refractive-index adhesives for light-emitting diode component fabrication.