High performance light-emitting devices

US7863632B2 · kind B2 · utility

Assignee

• National Research Council of Canada · CA

Inventors

• Li Li · Ottawa, CA
• Jerzy A. Dobrowolski · Ottawa, CA
• Daniel Poitras · Ottawa, CA

Key dates

• Filing date: Aug 23, 2004
• Grant date: Jan 4, 2011
• Expiry date: Mar 17, 2027

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10K85/631

Abstract

An organic light emitting device consists of a layered structure including a top multilayer stack, a bottom multilayer stack, a cavity layer between the top multilayer stack and the bottom multilayer stack, and an organic light emitting region within the cavity layer. The layered structure is constructed such that the product of phase factors ξ1 and ξ2 is. greater than 80% at the center of at least one emitting wavelength region and for a normal viewing angle, wherein where Ra− and Rb+ are the reflectance of the top and bottom multilayer stacks respectively, φa− and φb+ are the phase changes on reflection for the top and bottom multilayer stacks respectively, α1 β1 are respectively the real and imaginary parts of the phase thickness of the cavity layer, α2 and β2 are respectively the real and imaginary parts of the phase thickness of the light-emitting region at the operating wavelength of the device, x is the mean distance of light emitting region from the bottom multilayer stack, n and k are the refractive index and absorption coefficient of the cavity layer, θcavity is the emitting angle inside the cavity layer, and d is the physical thickness of said cavity layer. This conditio…