Multicolor organic light emitting devices

• US 5,721,160 A
• Filed: 04/15/1996
• Issued: 02/24/1998
• Est. Priority Date: 12/13/1994
• Status: Expired due to Fees

• Current Assignee: The Trustees of Princeton University (Princeton University)
• Original Assignee: The Trustees of Princeton University (Princeton University)
• Inventors: Burrows, Paul Edward, Sapochak, Linda Susan, McCarty, Dennis Matthew, Forrest, Stephen Ross, Thompson, Mark Edward
• Primary Examiner(s): TRINH, MICHAEL MANH
• Application Number:
  US08/632,316
• Time in Patent Office: 680 Days
• Field of Search: 438/28, 438/26, 438/22, 438/25, 438/125, 438/126, 438/127
• US Class Current: 438/28
• CPC Class Codes: C09K 11/06 containing organic luminescent materials
• CPC Class Codes: H01L 24/82 by forming build-up interconnects at chip-level, e.g. for high density interconnects [HDI] interconnection structure between a plurality of semiconductor chips H01L23/5389
• CPC Class Codes: H01L 27/156 two-dimensional arrays
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/12033 Gunn diode
• CPC Class Codes: H01L 2924/12041 LED
• CPC Class Codes: H01L 2924/12042 LASER
• CPC Class Codes: H01L 2924/12044 OLED
• CPC Class Codes: H10K 2102/3031 Two-side emission, e.g. transparent OLEDs [TOLED]
• CPC Class Codes: H10K 50/11 characterised by the electroluminescent [EL] layers
• CPC Class Codes: H10K 50/125 specially adapted for multicolour light emission, e.g. for emitting white light
• CPC Class Codes: H10K 50/14 Carrier transporting layers
• CPC Class Codes: H10K 50/828 Transparent cathodes, e.g. comprising thin metal layers
• CPC Class Codes: H10K 59/32 Stacked devices having two or more layers, each emitting at different wavelengths
• CPC Class Codes: H10K 59/80524 Transparent cathodes, e.g. comprising thin metal layers
• CPC Class Codes: H10K 85/10 Organic polymers or oligomers
• CPC Class Codes: H10K 85/111 comprising aromatic, heteroaromatic, or aryl chains, e.g. polyaniline, polyphenylene or polyphenylene vinylene
• CPC Class Codes: H10K 85/113 Heteroaromatic compounds comprising sulfur or selene, e.g. polythiophene
• CPC Class Codes: H10K 85/114 Poly-phenylenevinylene; Derivatives thereof
• CPC Class Codes: H10K 85/146 poly N-vinylcarbazol; Derivatives thereof
• CPC Class Codes: H10K 85/30 : Coordination compounds
• CPC Class Codes: H10K 85/322 : comprising boron
• CPC Class Codes: H10K 85/324 : comprising aluminium, e.g. Alq3
• CPC Class Codes: H10K 85/341 : Transition metal complexes, e.g. Ru(II)polypyridine complexes H10K85/331 takes precedence
• CPC Class Codes: H10K 85/60 : Organic compounds having low molecular weight H10K85/10 - H10K85/50 take precedence
• CPC Class Codes: H10K 85/611 : Charge transfer complexes
• CPC Class Codes: H10K 85/631 : Amine compounds having at least two aryl rest on at least one amine-nitrogen atom, e.g. triphenylamine
• CPC Class Codes: Y10T 428/26 : Web or sheet containing structurally defined element or component, the element or component having a specified physical dimension
• CPC Class Codes: Y10T 428/265 : 1 mil or less
• CPC Class Codes: Y10T 428/31678 : Of metal

Abstract

A multicolor organic light emitting device employs vertically stacked layers of double heterostructure devices which are fabricated from organic compounds. The vertical stacked structure is formed on a glass base having a transparent coating of ITO or similar metal to provide a substrate. Deposited on the substrate is the vertical stacked arrangement of three double heterostructure devices, each fabricated from a suitable organic material. Stacking is implemented such that the double heterostructure with the longest wavelength is on the top of the stack. This constitutes the device emitting red light on the top with the device having the shortest wavelength, namely, the device emitting blue light, on the bottom of the stack. Located between the red and blue device structures is the green device structure. The devices are configured as stacked to provide a staircase profile whereby each device is separated from the other by a thin transparent conductive contact layer to enable light emanating from each of the devices to pass through the semitransparent contacts and through the lower device structures while further enabling each of the devices to receive a selective bias.

Claims

1. A method of fabricating a hermetically packaged multicolor light emitting device (LED), comprising the steps of:

forming a first transparent conductive layer upon a transparent substrate;

masking said first conductive layer for depositing an SiO₂ layer thereupon in a concentric pattern;

forming on a portion of said first SiO₂ layer at least one multicolor LED, each including at least a first and a second organic light emitting devices (LED'"'"'s) stacked one upon the other to form a layered structure upon said first SiO₂ layer;

depositing via shadow masking a plurality of metal contacts or circuit paths each having one end terminating near an outer edge of said first SiO₂ layer, and each having another end terminating on an individual biasing electrode of said at least one multicolor LED;

depositing via shadow masking a second SiO₂ layer as a ring concentric with said first SiO₂ layer and over outer portions of said plurality of metal contacts but leaving exposed said one ends thereof;

depositing a ring of low temperature melting solder over and concentric with said second SiO₂ ring;

depositing on the bottom of a cover glass a metal ring positioned to be coincident with said ring of solder;

installing said cover glass over said substrate and at least one multicolor LED, with said ring of solder abutting against said metal ring on said cover glass;

placing the assembly in an inert gas atmosphere; and

heating said ring of solder to melt the solder for both forming an air tight seal, and entrapping said inert gas in an interior region between the bottom of said cover glass and underlying substrate.

2. The method of claim 1, wherein said multicolor LED forming step further includes forming a plurality of multicolor LED devices on said first SiO₂ layer.

3. The method of claim 1, wherein said inert gas includes dry nitrogen.

4. The method of claim 1, wherein said first transparent layer includes indium tin oxide (ITO).

5. The method of claim 4, further including the step of depositing a metal contact proximate an edge of and upon said ITO layer for serving as a cathode electrode.

6. The method of claim 2, further including the step of depositing a metal contact proximate an edge and upon said first transparent conductive layer for serving as a cathode electrode.

7. The method of claim 6, wherein said first transparent conductive layer includes indium tin oxide (ITO).