Liquid-phase epitaxial growth of InGaP and InGaAsP on GaAs_0.69P_0.31 substrates with application to visible light-emitting diodes

Good-quality In_0.37Ga_0.63P and In_0.2Ga_0.8As_0.27P_0.73 layers lattice-matched to GaAs_0.69P_0.31 epitaxial substrates were grown by liquid-phase epitaxy using a supercooling technique. By selection of an optimum growth condition, we can obtain the undoped layer with a low electron concentration of 3 × 10¹⁶ cm^-3 for In_0.37Ga_0.63P and 2 × 10¹⁶ cm^-3 for In_0.2Ga_0.8As_0.27P_0.73. Photoluminescence (PL) of the undoped, Te- and Zn-doped In_0.37Ga_0.63P and In_0.2Ga_0.8As_0.27P_0.73 layers is described in detail. The emission peaks of 300 and 10 K PL spectra for In_0.37Ga_0.63P and In_0.2Ga_0.8As_0.27P_0.73 are 590 and 568 nm and 639 and 615 nm, respectively. The visible light-emitting diodes (LEDs) employing In_0.37Ga_0.63P/In_0.2Ga_0.8As_0.27P_0.73/ In_0.37Ga_0.63P double heterostructure grown on GaAs_0.69P_0.31 substrates were fabricated. The LEDs exhibit a forward-bias turn-on voltage of 1.6-1.7 V, an ideality factor of approx. 2.0, an emission wavelength of approx. 670 nm and an external quantum efficiency of 0.20% at 60 mA.