Tellurium and zinc doping in In0.5Ga0.5P grown by liquid-phase epitaxy

In0.5Ga0.5P epitaxial layers doped with Te and Zn were grown on (100) GaAs substrates by liquid-phase epitaxy using a supercooling method. The lattice mismatch between the InGaP layer and the GaAs substrate decreases with increasing Te or Zn impurity concentration. The electrical properties of doped layers were determined by Hall measurements at 300 and 77 K. Room-temperature carrier concentrations ranging from 2×1017 to 3×1018 cm−3 for n-type and from 2×1017 to 2×1019 cm−3 for p-type dopants were obtained reproducibly. The full width at half maximum value of the 300 K photoluminescent spectrum increases with carrier concentration for both Te- and Zn-doped layers. The relative intensity of the 300 K photoluminescent peak increases with electron concentrations up to 3×1018 cm−3 for Te-doped layers, but it presents a maximum value at 1×1018 cm−3 for Zn-doped layers. The 14 K photoluminescent spectra show three distinctive peaks and their relative intensities change with hole concentrations. Finally, the relationship between the acceptor ionization energy and hole concentration is described.