White-emitting phosphors with high color-rendering index based on silver cluster-loaded zeolites and their application to near-UV LED-based white LEDs†
Abstract
Silver clusters confined in zeolites have emerged as promising functional materials in the optical field due to their characteristic color properties. However, single-phase white light phosphors based on silver cluster-loaded zeolites for fabricating white LEDs have been rarely achieved. In this paper, a luminescent material with tunable emission from green to cyan and white was developed using thermally-treated Ag+ ion-exchanged zeolite Y. The above-mentioned luminescence performance was proved to be affected by the mutative silver cluster species. Furthermore, an ideal white emitting material was achieved. Moreover, a white LED device with a high Ra of 92.3 was fabricated simply by combining a UV Chip-On-Board with the white emitting composite. Our results provide a novel method for the preparation of solid single-component white light materials applied for LEDs.