Magneto-photoluminescence in a type-II broken-gap n-GaInAsSb/ p-InAs heterojunction.

Magneto-photoluminescence in a single type-II broken-gap n-Ga0.94In0.06As0.13Sb0.87/ p-InAs heterostructure with a 2D electron channel at the heterointerface containing two occupied electron subbands has been studied in the spectral range 0.3–0.8 eV in high magnetic fields of up to 10 T at low temperatures ( T = 7 K). At photon energies in the range 0.5–0.8 eV, bulk photoluminescence from the layer of the n-GaInAsSb alloy was observed. In the low-energy part of the spectrum (0.3–0.45 eV), three narrow emission bands with photon energies hν a = 0.419 eV, hν b = 0.404 eV, and hν c = 0.384 eV and full widths at half-maximum FWHM = 4–7 meV were observed. These bands are due to radiative transitions of 2D electrons localized in the quantum well on the InAs side near the type-II heterointerface. The electron effective mass in the occupied subband E 2 was estimated to be m 2 = 0.027 m 0, which is close to the effective mass at the bottom of the InAs conduction band. [ABSTRACT FROM AUTHOR]