Concentration-dependent photoluminescence of Te-doped In _0.14Ga_0.86As_0.13Sb_0.87

Quaternary layers of N-typeIn_xGa_1-xAs _ySb_1-y were grown by liquid phase epitaxy on (100) GaSb substrates under lattice-matching conditions. Low-temperature photoluminescence spectra were obtained as a function of tellurium concentration. These spectra were interpreted taking into account the nonparabolicity of the conduction band. Calculations of the peak position and photoluminescence transitions were performed. Both the band filled as well as band tailing effects due to Coulomb interaction of free carriers with ionized impurities and shrinkage due to exchange interaction between free carriers were considered in order to properly account for the observed features of the photoluminescence spectra. It is shown that the band-to-band energy transition can be used to obtain the carrier concentration in N-typeIn_xGa_1-xAs_ySb _1-y, in the range from 1 × 10¹⁶ to 3.42 × 10¹⁸cm^-3.