CALCULATIONS OF PLASMA WAVELENGTH IN HIGHLY DOPED III-V SEMICONDUCTORALLAYS

A detailed study of the dependence of the plasma wavelength on the dop ing concentration in ternary and quaternary III-V semiconductor alloys has been made. The band-structure properties are included in the calc ulations by applying the triple-band effective-mass equations to an ex tended Drude formula. The results show that for high doping levels the plasma wavelengths of the considered materials (InAsxSb1-x, GaxIn1-xS b, GaAs1-xSbx, In1-xGaxAs, In-1-x,GaxAsyP1-y, and AlxGayIn1-x-yAs) sat urate into the 10-mu m-wavelength region (the smaller the band gap, th e larger the saturation wavelength). The optimal material group for th e realization of the plasma resonance for 10.6 mu m (CO2 lasers) seems to be In0.53Ga0.47As. Numerical fits for the plasma wavelength and th e optical effective mass are provided.