Semiconductor light emitting devices including in-plane light emitting layers

• US 7,808,011 B2
• Filed: 03/19/2004
• Issued: 10/05/2010
• Est. Priority Date: 03/19/2004
• Status: Expired due to Fees

• Current Assignee: Lumileds LLC (Apollo Global Management, Inc.)
• Original Assignee: Philips Lumileds Lighting Company LLC (Apollo Global Management, Inc.), Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: Krames, Michael R., Gardner, Nathan F., Epler, John E., Wierer, Jonathan J. Jr., Kim, James C.
• Primary Examiner(s): Mondt; Johannes P
• Application Number:
  US10/805,424
• Publication Number:
  US 20050205884A1
• Time in Patent Office: 2,391 Days
• Field of Search: 257/88, 257/89, 257/98, 257/99
• US Class Current: 257/98
• CPC Class Codes: H01L 25/0756 Stacked arrangements of devices
• 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 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H01L 2933/0083 Periodic patterns for optical field-shaping in or on the semiconductor body or semiconductor body package, e.g. photonic bandgap structures
• CPC Class Codes: H01L 33/105 with a resonant cavity structure
• CPC Class Codes: H01L 33/18 within the light emitting region
• CPC Class Codes: H01L 33/32 containing nitrogen
• CPC Class Codes: H01L 33/405 Reflective materials
• CPC Class Codes: H01L 33/46 Reflective coating, e.g. dielectric Bragg reflector

Abstract

A semiconductor light emitting device includes an in-plane active region that emits linearly-polarized light. An in-plane active region may include, for example, a {11 20} or {10 10} InGaN light emitting layer. In some embodiments, a polarizer oriented to pass light of a polarization of a majority of light emitted by the active region serves as a contact. In some embodiments, two active regions emitting the same or different colored light are separated by a polarizer oriented to pass light of a polarization of a majority of light emitted by the bottom active region, and to reflect light of a polarization of a majority of light emitted by the top active region. In some embodiments, a polarizer reflects light scattered by a wavelength converting layer.

Claims

1. A structure comprising:

a first epitaxial structure comprising a first active region sandwiched between a first n-type region and a first p-type region, the first active region configured to emit light having a polarization ratio, defined as (|I_p−

I_s|/(I_p+I_s))×

100% where I_p is an intensity of vertically polarized light and I_s is an intensity of horizontally polarized light, of at least 50% when forward biased;

a polarizer disposed in a path of light emitted by the first active region, wherein the polarizer is oriented to transmit light of a polarization of a majority of light emitted by the first active region; and

a second epitaxial structure comprising a second active region sandwiched between a second n-type region and a second p-type region, the second active region configured to emit light having a polarization ratio of at least 50% when forward biased;

wherein;

the polarizer comprises a plurality of evenly spaced, parallel metal lines;

the polarizer configured to serve as an electrical contact between the first and second epitaxial structures;

the polarizer is disposed between the first epitaxial structure and the second epitaxial structure; and

the polarizer is oriented to reflect light of a polarization of a majority of light emitted by the second active region.

2. The structure of claim 1 wherein the first active region and the second active region emit light of a same color.

3. The structure of claim 1 wherein the first active region and the second active region emit light of different colors.