Visible narrow-band DC electroluminescence

The need of low-voltage de electroluminescent devices that emit in the visible portion of the spectrum is well-recognized. Devices composed of p-n junctions of binary or ternary III-V semiconductors exhibit high injection-efficiency but have poor internal quantum-efficiency, particularly in the green where the eye-response is the greatest. Furthermore, the all-important consideration of contrast as a criterion for display-effectiveness makes luminescence in a narrow visible band all the more useful. Such narrow-bandedness is not present in a nonlasing mode of a III-V device.