Transparent electron blocking hole transporting layer

US9419194B2 · kind B2 · utility

Assignee

• Palo Alto Research Center Incorporated · US

Inventors

• John E. Northrup · Palo Alto, US
• Christopher L. Chua · San Jose, US

Key dates

• Filing date: Aug 13, 2013
• Grant date: Aug 16, 2016
• Expiry date: Sep 11, 2033

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10H20/832

Abstract

A light emitting diode includes an active region configured to emit light, a composite electrical contact layer, and a transparent electron blocking hole transport layer (TEBHTL). The composite electrical contact layer includes two materials. At least one of the two materials is a metal configured to reflect a portion of the emitted light. The TEBHTL is arranged between the composite electrical contact layer and the active region. The TEBHTL has a thickness that extends at least a majority of a distance between the active region and the composite electrical contact layer. The TEBHTL has a band-gap greater than a band-gap of light emitting portions of the active region. The band-gap of the TEBHTL decreases as a function of distance from the active region to the composite electrical contact layer over a majority of the thickness of the TEBHTL.