Electroluminescence of InAs-GaSb heterodiodes

The electroluminescence of a Type II InAs-GaSb superlattice heterodiode has been studied as a function of injection current and temperature in the spectral range between 3 and 13 µm. The heterodiode comprises a Be-doped midwavelength infrared (MWIR) superlattice with an effective bandgap around 270 meV and an undoped long wavelength infrared (LWIR) superlattice with an effective bandgap of 115 meV. At high injection currents and elevated temperatures the band to band transitions of both superlattices can be observed. By increasing the temperature the intensity of the MWIR emission component shows a well defined thermally activated increase. The activation energy of the Beryllium doping was evaluated to be 28 meV.