Superlinearity and temperature dependence of electroluminescence in heterostructures with deep AlSb/InAs(1-x)Sb_x/AlSb quantum well

摘要

We report on superlinear electroluminescent structures based on AlSb/InAsi_(1-x)Sb_x/AlSb deep quantum well grown by MOVPE on n-GaSb:Te substrate. Dependence of the electroluminescence (EL) spectra and optical power on the drive current in nanoheterostructures with AlSb/InAs_(1-x)Sb_x/AlSb quantum well at 77 - 300 K temperature range was studied. Intensive two-band superlinear EL in the 0.5 - 0.8 eV photon energy range was observed. Optical power enhancement with the increasing drive current at room temperature is caused by the contribution of the additional electron-hole pairs due to the impact ionization by the electrons heated at the high band offset between AlSb and the first electron level E_(el) in the InAsSb QW. Study of the EL temperature dependence at 90 - 300 K range enabled us to define the role of the first and second heavy hole levels in the radiative recombination process. It was shown that with the temperature decrease, the relation between the energies of the valence band offset and the second heavy hole energy level changes due to the temperature transformation of the energy band diagram. That is why the EL spectrum revealed radiative transitions from the first electron level E_(el) to the first hole level E_(hl) in the whole temperature range (90 - 300 K) while the emission band related with the transitions to the second hole level occurred only at T ＞ 200 K.