Method for producing light-emitting elements

• US 8,852,977 B2
• Filed: 01/11/2013
• Issued: 10/07/2014
• Est. Priority Date: 08/06/2010
• Status: Expired due to Fees

• Current Assignee: JOLED Inc.
• Original Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Inventors: Nishiyama, Seiji
• Primary Examiner(s): STARK, JARRETT J
• Application Number:
  US13/739,290
• Publication Number:
  US 20130143346A1
• Time in Patent Office: 634 Days
• Field of Search: 438/34, 257/E51.018, 213/498
• US Class Current: 438/34
• CPC Class Codes: H05B 33/10 Apparatus or processes specially adapted to the manufacture of electroluminescent light sources
• CPC Class Codes: H10K 50/17 Carrier injection layers
• CPC Class Codes: H10K 50/805 Electrodes
• CPC Class Codes: H10K 59/122 Pixel-defining structures or layers, e.g. banks
• CPC Class Codes: H10K 59/131 Interconnections, e.g. wiring lines or terminals
• CPC Class Codes: H10K 59/173 comprising banks or shadow masks
• CPC Class Codes: H10K 59/805 Electrodes

Abstract

A light-emitter is configured so that at least a hole injection layer and a light-emitting layer are laminated between a first electrode and a second electrode, and the light-emitting layer is formed in an area defined by a bank. In the area defined by the bank, the hole injection layer is formed so as to have a recess in an upper surface thereof. An upper peripheral edge of the recess is covered with a part of the bank. The light-emitting layer is formed with respect to the recess formed in the hole injection layer by a laser transfer method.

Claims

1. A method for manufacturing a light-emitter including a first electrode, a laminate disposed on the first electrode that includes a charge injection transport layer and a light-emitting layer, a second electrode disposed on the laminate, and a bank that defines an area in which the light-emitting layer is to be formed, the method comprising:

forming the charge injection transport layer;

forming a bank material layer that forms the bank on the charge injection transport layer;

removing a portion of the bank material layer to partially expose the charge injection transport layer;

heat-treating a remaining portion of the bank material layer; and

forming the light-emitting layer on an exposed surface of the charge injection transport layer after the heat treatment, wherein

the charge injection transport layer is made from a material that is eroded when exposed to a liquid used while the charge injection transport layer is partially exposed, the charge injection transport layer having a recess in the exposed surface thereof so that a bottom of the recess is lower than a bottom surface of the remaining portion of the bank material layer, the recess being formed by the exposed surface eroded by the liquid, the remaining portion of the bank material layer being made fluid so that the bank material layer extends to cover an upper peripheral edge of the recess, the light-emitting layer being formed by using a laser transfer method.

2. The method for manufacturing the light-emitter of claim 1, wherein the charge injection transport layer is a hole injection layer made from one of a metal oxide, a metal nitride, and a metal oxynitride.

3. The method for manufacturing the light-emitter of claim 2, wherein a hole transport layer that transports holes from the hole injection layer to the light-emitting layer is interposed between the hole injection layer and the light-emitting layer.

4. The method for manufacturing the light-emitter of claim 1, wherein the charge injection transport layer is made from a material that is eroded when exposed to a liquid used for forming the bank.

5. The method for manufacturing the light-emitter of claim 4, wherein the liquid is water or a TMAH solution.

6. The method for manufacturing the light-emitter of claim 1, wherein the bank is formed so that a part of the bank reaches a bottom of the recess and that a side surface of the bank slopes upward from the bottom of the recess to a top of the bank.

7. The method for manufacturing the light-emitter of claim 1, wherein the bank is formed so that a part of the bank is out of contact with a bottom of the recess.

8. The method for manufacturing the light-emitter of claim 1, wherein the bank is formed so as to include an insulating material.

9. The method for manufacturing the light-emitter of claim 1, wherein the light-emitting layer comprises an organic EL layer.

10. The method for manufacturing the light-emitter of claim 1, wherein the charge injection transport layer is formed so as to extend laterally along a bottom surface of the bank.

11. The method for manufacturing the light-emitter of claim 1, wherein the upper peripheral edge of the recess is formed so as to comprise a convex portion composed of (i) a part of the upper surface of the charge injection transport layer in which the recess is not formed, and (ii) an inner side surface of the recess.

12. The method for manufacturing the light-emitter of claim 1, wherein, in the forming the light-emitting layer, for each of a plurality of areas defined by the bank, a transfer substrate having a transfer layer of a corresponding color is irradiated with a laser to sublimate and transfer the transfer layer onto the charge injection transport layer, thereby forming a plurality of light-emitting layers of different colors.

13. The method for manufacturing the light-emitter of claim 12, wherein the forming the light-emitting layer includes the successive steps of:

irradiating, with a laser, a first transfer substrate including a photothermal conversion layer and a first transfer layer of a first luminescent color laminated on the photothermal conversion layer, to sublimate and transfer the first transfer layer, thereby forming the light-emitting layer of the first luminescent color, and

irradiating, with a laser, a second transfer substrate including the photothermal conversion layer and a second transfer layer of a second luminescent color laminated on the photothermal conversion layer, to sublimate and transfer the second transfer layer, thereby forming the light-emitting layer of the second luminescent color.