Ultra-High-Efficiency Deep-Green LEDs Based on Quantum-Dots on Native AlN Substrates

The proposed effort addresses the important need to develop an efficient direct emission source in the 555-585 nm (deep-green) wavelength range, corresponding to the peak photopic response of the human eye. Current limitations in extending the operatingwavelengths of III-N devices beyond the blue-green region of the spectrum are overcome by combining the quantum dot approach, in which a red shift is achieved by increasing the amount of indium in the active region, and epitaxial growth on native AlNsubstrates, which provide for greatly reduced dislocation densities and the opportunity to utilize non-polar substrate orientations, which, in turn, may provide additional device operation efficiencies due to increase electron-hole overlap in the activeregion.