High-brightness blue and green light-emitting diodes

We report high-brightness blue and green light-emitting diodes (LEDs) based on II–VI heterostructures grown by molecular beam epitaxy on ZnSe substrates. The devices consist of a 2–3 μm thick layer of n-type ZnSe:Cl, a ∼0.1 μm thick active region of Zn0.9Cd0.1Se (blue) or ZnTe0.1Se0.9 (green), and a 1.0 μm thick p-type ZnSe:N layer. The blue LEDs produce 327 μW (10 mA, 3.2 V), with the light output sharply peaked at 489 nm, and exhibit an external quantum efficiency of 1.3%. The green LEDs produce 1.3 mW (10 mA, 3.2 V) peaked at 512 nm, corresponding to an external quantum efficiency of 5.3%. In terms of photometric units, the luminous performance (luminous efficiency) of the devices is 1.6 lm/W (blue) and 17 lm/W (green), respectively, when operated at 10 mA.