Blue light emitting diodes grown on freestanding (11-20) a -plane GaN substrates

Visible blue light emitting diodes have been produced on freestanding nonpolar GaN (11-20) a-plane substrates by metal-organic chemical vapor deposition. The growth conditions have been optimized for smooth growth morphology of GaN nonpolar homoepitaxial layers without surface features, leading to light emitting diode epitaxial structures that are free of crystalline defects such as threading dislocations and stacking faults. Electroluminescence of light emitting diodes exhibit peak wavelengths of ∼450nm and are independent of current level at low current densities before the heating effects are evidenced.