III-N Based Material Structures and Circuit Modules Based on Strain Management

Current state-of-the-art optoelectronic devices are based on either lattice-matched or biaxially strained wurtzite III-nitride materials. Their performance is limited by the low hole conductivity in group-III nitride materials, which is due in part to the high relative hole mass in nitrides, resulting in a very low hole mobility. Decreasing the holes’ effective mass results in significant performance improvements in photonic devices.

Researchers at the University of California, Santa Barbara have incorporated strain engineering into electronic and photonic nitride heterostructures, resulting in an upward movement of the light hole band and formation of holes with a relative mass less than electrons. This technology enables significant improvement to the performance of hole-based transistors and enables the fabrication of integrated circuits combining electron and hole-based transistors. In addition, the technology enables improvements to the performance of optoelectronic devices such as LEDs, but especially lasers, through a significant reduction in the threshold carrier density. By utilizing strain as proposed by this technology, the performance of all p-type and n-type III-nitride electronic devices can be enhanced.