Aluminum-cladding-free Nonpolar III-Nitride LEDs and LDs

Brief Description

A nonpolar III-nitride LED or LD that does not require any aluminum-containing cladding layers, because the quantum well active region is thick enough to function as an optical waveguide for the device.  

Background

Most existing GaN-based edge-emitting laser diodes are c-plane structures. To achieve the most effective optical mode in these devices, the inclusion of aluminum-containing waveguide cladding layers is required, however these layers present significant epitaxial growth challenges as well as reduced material quality and problems for reactor stability and reproducibility.

Description

UC Santa Barbara researchers have created a nonpolar III-nitride LED or LD that does not require any aluminum-containing cladding layers, because the quantum well active region is thick enough to function as an optical waveguide for the device. The exclusion of Al-containing waveguide layers allows for simpler epitaxial growth techniques, helps reduce problems with tensile strain and cracking in Al-containing waveguide layers, and creates higher crystal quality material. The elimination of Al-containing waveguide cladding layers allows for the fabrication of III-nitride-based LDs in the same way as III-nitride-based LEDs.

Advantages

• Higher crystal quality material 
• Lower threshold current densities
• Reduced voltage operation
• Longer lifetimes
• Lower production costs

Patent Status

Applications

• LEDs and LDs