ZnSe/BeTe type-II LEDs emitting between 640 and 515 nm

We report the growth and characterization of LEDs with wavelengths from 640 to 515 nm based on ZnSe/BeTe type-II transitions. The spatially indirect transition shows bright luminescence at room temperature probably due to a strong carrier confinement at the interface. In addition, the device lifetime reaches values above 1000 h. This relatively good device stability can be explained by a reduction of stacking faults at the growth start with BeTe, the reduction of strain in the active zone, the absence of nitrogen-doped ZnSe, and the fully pseudomorphic p-BeTe contact.