Light emitting diodes

Abstract

A light emitting device comprises first and second semiconductor layers (14,16) and an emitting layer (18) between the semiconductor layers (14,16), arranged to form a light emitting diode,-a gap (30) in one of the layers; and a metal (34) located in the gap (30) and near enough to the emitting layer (18) to permit surface plasmon coupling between the metal (34) and the emitting layer (18).

Description

technical field [0001] The present invention relates to light emitting diodes (LEDs), and more particularly to white LEDs, although it can also be used in LEDs of other colors. Background technique [0002] Due to the increasing energy shortage worldwide and the threat of global warming, the development of white solid-state lighting devices, mainly based on III-nitride blue LED chips with yellow phosphors, has become extremely important at present. Current commercial white light-emitting diodes (LEDs) are generally based on blue epitaxial wafers with high crystalline quality and are usually very expensive. This also makes such LEDs expensive and thus limits their use in general lighting. Therefore, there is a need to develop a new technology for manufacturing LEDs, especially white LEDs, which have higher luminous efficacy but have low prices that can be easily accepted by the market, thereby replacing conventional lighting sources. However, there are many challenges in or...

AI Technical Summary

Problems solved by technology

However, methods like this require ex situ deposition due to unused precursors

In addition, the deposition of such metal islands will lead to a substantial degradation of the optical properties of the emissive layer, which will eventually terminate the emission

In practice, this method degrades the lattice structure of the emissive layer and can eventually lead to failure of the LED

[0006] Second, there is a self-absorption problem in the current fabrication of phosphor-converted white LEDs

The intensity of blue light generally remains much higher than the yellow emission from wavelength converting materials, resulting in severe color reproduction problems as well as blue tinge in most existing white LEDs

Images