US 12,446,378 B2
Current spreading structure for light-emitting diode
Jianping Zhang, Arcadia, CA (US); Ying Gao, Fremont, CA (US); and Ling Zhou, Dublin, CA (US)
Assigned to BOLB Inc., Livermore, CA (US)
Filed by BOLB Inc., Livermore, CA (US)
Filed on Sep. 29, 2022, as Appl. No. 17/936,802.
Prior Publication US 2024/0128419 A1, Apr. 18, 2024
Int. Cl. H10H 20/857 (2025.01); H10H 20/816 (2025.01); H10H 20/852 (2025.01)
CPC H10H 20/857 (2025.01) [H10H 20/852 (2025.01)] 20 Claims
OG exemplary drawing
 
1. An apparatus, comprising:
a current spreading base with at least one n-contact, the current spreading base having a small n-type resistivity to promote lateral electron flow;
a current spreading cap on top of the current spreading base, the current spreading cap with a large n-type resistivity to suppress vertical electron flow and promote lateral electron flow, wherein the current spreading cap has a resistivity of a few tens to thousands of Ωcm and the current spreading cap includes multiple layers of different bandgaps;
a light-emitting active region on top of the current spreading cap; and
a p-type structure on top of the light-emitting active region with a p-contact.
 
14. An apparatus, comprising:
a current spreading base with at least one n-contact, the current spreading base having a small n-type resistivity to promote lateral electron flow;
a current spreading cap on top of the current spreading base, the current spreading cap with a large n-type resistivity to suppress vertical electron flow and promote lateral electron flow;
a light-emitting active region on top of the current spreading cap;
a p-type structure on top of the light-emitting active region with a p-contact;
a template layer attached to the current spreading base; the template layer has a roughened surface for light extraction; and,
n-contacts extending from the template layer into the current spreading base.