Our goal is to advance the fundamental science and technology to both understand factors that limit efficiencies for light emitting diode-based lighting and to provide innovative and viable solutions to current roadblocks. We intend to achieve these goals by: (1) control and elucidation of the carrier loss mechanisms on nonpolar/semipolar GaN LEDs; (2) growth of defect-free bulk GaN crystals; and (3) full-spectrum lighting using an all semiconductor-based emission region; (4) grow devices on nonpolar or semipolar planes to avoid the detrimental effects of polarization-induced electric fields in multiquantum wells arising from discontinuities in spontaneous and piezoelectric polarization at heterointerfaces; and (5) develop and apply photonic crystals to enhance the extraction of light from LEDs.
Figure: SEM image of a cross-section of a LED withdouble embedded PhC. The cross-section is cut along theGK direction of the p-side PhC. The gratings of the twoPhC are misaligned by 22o which explains the differencein observation of the PhC holes.