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) frown 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 (SPVT (TM)) process. The device structures consisted of a 2-3 mu m thick layer of n-type ZnSe:Cl a 0.1 mu m thick active region of multiple quantum well (MQW) Zn0.9Cd0.1Se (blue/green) or ZnTe0.1Se0.9 (green), and a 1.0 mu m 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, 4 V) 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).