Light-emitting element and display device

• US 9,185,772 B2
• Filed: 07/28/2009
• Issued: 11/10/2015
• Est. Priority Date: 07/28/2009
• Status: Active Grant

• Current Assignee: Pioneer Corporation
• Original Assignee: Pioneer Corporation
• Inventors: Yoshioka, Toshihiro, Uchida, Toshiharu
• Primary Examiner(s): REAMES, MATTHEW L
• Application Number:
  US13/376,453
• Publication Number:
  US 20120138975A1
• Time in Patent Office: 2,296 Days
• Field of Search: 257/40, 313/504
• US Class Current: 1/1
• CPC Class Codes: H05B 33/14 characterised by the chemical or physical composition or the arrangement of the electroluminescent material , or by the simultaneous addition of the electroluminescent material in or onto the light source
• CPC Class Codes: H05B 33/145 Arrangements of the electroluminescent material
• CPC Class Codes: H10K 2102/3026 Top emission
• CPC Class Codes: H10K 50/14 Carrier transporting layers
• CPC Class Codes: H10K 50/852 comprising a resonant cavity structure, e.g. Bragg reflector pair
• CPC Class Codes: H10K 59/35 comprising red-green-blue [RGB] subpixels
• CPC Class Codes: H10K 59/876 comprising a resonant cavity structure, e.g. Bragg reflector pair

Abstract

A light-emitting element and a display device having a resonator structure which has a small luminance fluctuation, even if a film thickness is deviated from a designed value, thereby resulting in a variation in resonator optical path length. There are included: a first reflective member; a second reflective member; and a light-emitting layer provided therebetween, and there is provided a resonator structure that transmits part of light by the first reflective member or the second reflective member, the light being resonated between the first reflective member and the second reflective member. The resonator structure has at least two or more resonance spectral peaks at respective wavelengths in a visible light range with a wavelength of a maximum value relative luminosity being a border line and an emission output spectrum has at least two or more peaks at respective wavelengths based on the resonance spectral peaks.

Claims

1. A light-emitting element comprising:

an anode having a reflective electrode and a transparent electrode;

a cathode; and

an organic layer provided between the anode and the cathode,

wherein the light-emitting element has a resonance spectrum having a primary resonance peak whose central wavelength is positioned on a long wavelength side with respect to a wavelength at which a relative luminosity takes a maximum value and a secondary resonance peak whose central wavelength is positioned on a short wavelength side with respect to the wavelength at which the relative luminosity takes the maximum value, and

the light-emitting element has an emission output spectrum having

a primary peak whose central wavelength positioned on a long wavelength side with respect to the wavelength at which the relative luminosity takes the maximum value and a secondary peak whose central wavelength is positioned on a short wavelength side with respect to the wavelength at which the relative luminosity takes the maximum value and which has an emission intensity smaller than that of the primary peak.

2. The light-emitting element according to claim 1, wherein the organic layer emits light having an internal emission spectrum which has a primary internal emission peak whose central wavelength is positioned on a long wavelength side with respect to the wavelength at which the relative luminosity takes the maximum value and a secondary internal emission peak whose central wavelength is positioned on a short wavelength side with respect to the wavelength at which the relative luminosity takes the maximum value and which has an emission intensity smaller than that of the primary internal emission peak, and the primary peak corresponds to the primary internal emission peak and the primary resonance peak, and the secondary peak corresponds to the secondary internal emission peak and the secondary resonance peak.

3. An organic electroluminescence display device comprising the light-emitting element according to claim 1.

4. The light-emitting element according to claim 1, wherein the emission intensity of the secondary peak is less than 10% of that of the primary peak.