Low-Cost Zinc Oxide for High-Power-Output, GaN-Based LEDs (UC Case 2010-183)

Brief Description

UC Santa Barbara researchers have improved the performance of GaN LEDs through the addition of ZnO layers to the LED’s surfaces.

Background

To improve the light extraction efficiency of LEDs, transparent conductive oxides (TCOs) with high refractive indices — such as indium-tin-oxide (ITO), zinc oxide (ZnO), aluminum-doped-zinc-oxide (AZO) — are widely used. Films of these materials increase the probability of light escaping the LED through the TCO, thus increasing overall light output. ITO, however, is cost prohibitive, making zinc oxide films a better choice for commercial scalability. 

Description

UC Santa Barbara researchers have improved the performance of GaN LEDs through the addition of ZnO layers to the LED’s surfaces. These layers can improve the light extraction, heat dissipation, and current distribution of the device. The method of depositing ZnO by a low-temperature, aqueous route is low-cost and flexible, and can be used before or after the LED fabrication processing, resulting in low-cost, high-light-output GaN LED devices.

Advantages

• Increased light output
• Low-cost fabrication

Applications

• LEDs
• Solar cells
• GaN-based devices

Patent Status