Blue and green light-emitting diode structures grown by molecular beam epitaxy on ZnSe substrates

We report the first double-heterostructure blue, blue/green, and green light emitting devices (LEDs) grown by molecular beam epitaxy (MBE) on ZnSe substrates. The II-VI heterostructures were grown on (100) ZnSe substrates produced at Eagle-Picher Laboratory by the seeded physical vapor transport (SPVTTM) process. The device structures consisted of a 2-3 μm thick layer of n-type ZnSe:Cl a 0.1 μm thick active region of multiple quantum well (MQW) Zn0.9Cd0.1Se (blue/green) or ZnTe0.1Se0.9 (green), and a 1.0 μm thick p-type ZnSe:N layer. Deep blue emitting devices composed of Zn0.9Mg0.1S0.15Se0.85 lattice-matched cladding layers and a MQW ZnSe active region were also fabricated. The diodes emit blue-to-green electroluminescence at 300 K with emission peaks occurring at 466 to 512 nm depending on the type of active region employed. The brightest devices are the green LEDs which produce 1.29 mW (10 mA, 4V) peaked at 512 nm. This corresponds to an external efficiency of 3.2%. In terms of photometric units, the luminous performance of the devices is 13.6 lm/W (at 10 mA).