ZnSe/BeTe type-II light emitting diodes

We report on the growth and characterization of LEDs with wavelengths from 640 to 515 nm based on ZnSe/BeTe type-II transitions. Despite a spatially i ndirect transition the LEDs show bright luminescence at room temperature pr obably due to a strong carrier confinement at the interface. In addition, t he device lifetime reaches values above 1000 h at 20 A/cm(2). This good dev ice stability can be explained by a small number of stacking faults at the GaAs-BeTe interface, the reduction of strain in the active zone, the absenc e of nitrogen-doped ZnSe, and the fully pseudomorphic p-BeTe contact.