Electroluminescence in n-GaSb/InAs/p-GaSb Heterostructures with a Single Quantum Well Grown by MOVPE

Resumo

The electroluminescent characteristics of a type-II n-GaSb/n-InAs/p-GaSb heterostructure with a single deep quantum well grown by metalorganic vapor-phase epitaxy are investigated. The energy-band diagram of the structure and the positions of the electron and heavy-hole energy levels are calculated. The analysis of the current–voltage characteristics demonstrates that the dark current in the structure under study flows via the tunneling mechanism. Intense electroluminescence characterized by a weak temperature dependence was observed in the spectral range of 3–4 μm at T = 77 and 300 K. The main electroluminescence band (hν = 0.40 eV at 77 K) corresponds to direct radiative transitions between electrons from level E₁ in the InAs quantum well and heavy holes from the continuum at the n-GaSb/n-InAs heterointerface. A low-intensity electroluminescence band at hν = 0.27 eV (T = 77 K) originates from indirect (tunneling) transitions from the first electron level in the quantum well to the second level of heavy holes localized in the valence-band “notch” at the n-InAs/p-GaSb heterointerface.