Organic light active devices with particulated light active material in a carrier matrix

• US 7,256,427 B2
• Filed: 02/26/2003
• Issued: 08/14/2007
• Est. Priority Date: 11/19/2002
• Status: Expired due to Fees

• Current Assignee: Articulated Technologies, LLC
• Original Assignee: Articulated Technologies, LLC
• Inventors: Daniels, John James
• Primary Examiner(s): Pham; Long
• Application Number:
  US10/375,728
• Publication Number:
  US 20040097005A1
• Time in Patent Office: 1,630 Days
• Field of Search: 257/40, 257/79, 257/89
• US Class Current: 257/89
• CPC Class Codes: H01L 27/14627 Microlenses
• CPC Class Codes: H01L 27/148 Charge coupled imagers individual charge coupled devices H01L29/765
• CPC Class Codes: H10K 50/11 characterised by the electroluminescent [EL] layers
• CPC Class Codes: H10K 50/182 OLED comprising a fiber structure
• CPC Class Codes: H10K 50/80 Constructional details
• CPC Class Codes: H10K 59/13 comprising photosensors that control luminance
• CPC Class Codes: H10K 59/32 Stacked devices having two or more layers, each emitting at different wavelengths
• CPC Class Codes: H10K 71/12 using liquid deposition, e.g. spin coating
• CPC Class Codes: H10K 71/13 using printing techniques, e.g. ink-jet printing or screen printing

Abstract

A light active device includes a semiconductor particulate dispersed within a carrier material. A first contact layer is provided so that on application of an electric field charge carriers having a polarity are injected into the semiconductor particulate through the conductive carrier material. A second contact layer is provided so that on application of the electric field to the second contact layer charge carriers having an opposite polarity are injected into the semiconductor particulate through the conductive carrier material. The semiconductor particulate comprises at least one of an organic and an inorganic semiconductor. The semiconductor particulate may comprise an organic light active particulate that includes at least one conjugated polymer. When an electric field is applied between the first and second contact layers to the semiconductor particulate through the conductive carrier material, the second contact layer becomes positive relative to the first contact layer and charge carriers of opposite polarity are injected into the semiconductor particulate. The opposite polarity charge carriers combine to form in the conjugated polymer charge carrier pairs which decay radiatively so that radiation is emitted from the conjugated polymer. In this case, the inventive light active device acts as a light emitting diode.

Claims

1. A voltage controlled light active device for emitting two or more colors of light, comprising:

a first electrode;

a second electrode disposed adjacent to the first electrode and defining a gap therebetween;

a light active layer comprised of a mixture of a light active particulate and a conductive carrier material, said mixture being disposed within said gap,

said light active particulate comprised of

first emitting particles including a first electroluminescent conjugated polymer, the first emitting particles emitting a number of photons of a first color in response to a first turn-on voltage applied to the electrodes and emitting a different number of photons of the first color in response to other turn-on voltages,

said light active particulate further comprised of second emitting particles, the second emitting particles emitting a number of photons of a second color in response to a second turn-on voltage and a different number of photons of the second color in response to other turn-on voltages.

2. A light emitting device comprising:

a first electrode;

a second electrode disposed adjacent to said first electrode and defining a gap therebetween;

a mixture comprising light active particulate dispersed within a conductive carrier material, said mixture being disposed within said gap and emitting light in response to an applied voltage,

said light active particulate comprising

a plurality of first particles having a first electroluminescent conjugated polymer emitting a first number of photons of a first color in response to a first turn-on voltage applied to said first and second electrodes and emitting a second number of photons of said first color in response to other turn-on voltages, and

a plurality of second particles having a second electroluminescent conjugated polymer emitting a third number of photons of a second color in response to a second turn-on voltage applied to said first and second electrodes and fourth number of photons of the second color in response to said other turn-on voltages.

3. The light emitting device of claim 2 wherein said conductive carrier is comprised of an electrically conductive material.

4. The light emitting device of claim 2 wherein at least one of said plurality of first particles and said plurality of second particles includes members selected from the group consisting of polythiophenes, poly(paraphenylenes), and poly(paraphenylene vinylene), at least some of said members having substituents selected from the group consisting of alkyl, alkoxy, cycloalkyl, cycloalkoxy, flouroalkyl, alkylphenylene, and alkoxyphenylene vinylene.