ORGANIC ELECTROLUMINESCENT CELLS HAVING A TUNNEL INJECTION CATHODE

• US 3,710,167 A
• Filed: 07/02/1970
• Issued: 01/09/1973
• Est. Priority Date: 07/02/1970
• Status: Expired due to Term

• Current Assignee: Alvin Malcolm Goodman, Joseph Dresner
• Original Assignee: Alvin Malcolm Goodman, Joseph Dresner
• Inventors: Goodman, Alvin Malcolm, Dresner, Joseph
• Primary Examiner(s): Demeo, Palmer C.
• Application Number:
  US05/051,898
• Time in Patent Office: 922 Days
• Field of Search: 313/18A,109.5,18D,18R
• US Class Current: 313/504
• CPC Class Codes: H05B 33/12 Light sources with substantially two-dimensional radiating surfaces
• CPC Class Codes: H05B 33/22 characterised by the chemical or physical composition or the arrangement of auxiliary dielectric or reflective layers
• CPC Class Codes: H10K 50/82 Cathodes

Abstract

An electroluminescent cell comprises an anthracene layer having an anode and cathode thereon. The cathode of the novel cell is of the tunnel injection type. A typical cathode consists of a 10-100 A. thick layer of silicon dioxide deposited over a degenerate n type silicon body. The silicon dioxide layer of the cathode is placed in contact with the anthracence layer. The anode should provide hole injection into the anthracence layer. A preferred anode is a film of copper oxide and copper iodide.

Claims

2. a layer of an organic phosphor over said tunnel-injection layer and,

3. The electroluminescent cell recited in claim 1 wherein said organic phosphor has an electron trap density in the order of 1014 traps/cc. or less.

4. The electroluminescent cell recited in claim 1 wherein said phosphor layer consists of phosphor grains which are monocrystalline in the direction of current flow.

5. The electroluminescent cell recited in claim 1 wherein said dielectric has dielectric constant of less than 5.

6. The electroluminescent cell recited in claim 1 wherein said electrode material is n-type degenerate silicon and wherein said dielectric layer is SiO2 having a thickness of from 10-100 A.

7. The electroluminescent cell recited in claim 1 wherein said anode comprises a member selected from the group consisting of a tin oxide, indium oxide, a mixture of cuprous oxide and cuprous iodide, gold, platinum, a selenium-tellurium alloy and p type silicon having a 10-100 A. thick layer of silicon dioxide thereon.

8. The electroluminescent cell recited in claim 1 wherein said anode comprises a transparent film selected from a member of the group consisting of a mixture of copper oxide and copper iodide, tin oxide and indium oxide, said film having a transparent film of tellurium thereover, said tellurium film being no more than several atomic layers thick.

9. The electroluminescent cell recited in claim 1 wherein said anode has a mesh-like configuration.

10. A cell according to claim 1 wherein said phosphor layer is less than 10 micrometers in thickness.

11. A cell according to claim 1 wherein said phosphor layer contains anthracene.

12. A cell according to claim 1 wherein said cathode is spaced from said anode by an additional thickness of the dielectric layer around the periphery of said cell, which thickness defines the thickness of said phosphor layer.

13. A cell according to claim 12 wherein said peripheral dielectric thickness is from 1 to 10 micrometers.

14. An electroluminescent devise comprising: