Tunnel contact junction native-oxide aperture and mirror vertical-cavity surface-emitting lasers and resonant-cavity light-emitting diodes

Vertical-cavity surface-emitting lasers (VCSELs) and resonant-cavity light-emitting diodes (RCLEDs) are demonstrated with high index contrast distributed Bragg reflectors (DBRs) on either side of a lambda-thickness cavity (lambda similar to 980 nm). The devices, with tunnel contact junctions making possible lateral electron current excitation, have a lower 6.5 period native-oxide-based AlxOy/GaAs DBR and an upper reflector that is either a 2-4 period AlxOy/GaAs DBR, a 1-2 period SiO2/ZnSe DBR, lambda/4-thickness layer of AlxOy (antireflecting), or no mirror at all. The AlxOy/GaAs DBRs and a buried-oxide-defined current aperture are formed by selective oxidation of the high Al composition AlxGa1-xAs layers. Device characteristics are observed as a function of the upper DBR periodicity (reflectivity). Devices with upper reflectivities of R greater than or similar to 99% operate as VCSELs while those with less reflectivity R less than or similar to 96% operate as RCLEDs, some with external differential quantum efficiencies as high as eta similar to 27% and narrow spectral emission (Delta lambda similar to 50 Angstrom). (C) 1999 American Institute of Physics. [S0003-6951(99)00107-2].