Abstract
Good-quality In 0.37 Ga 0.63 P and In 0.2 Ga 0.8 As 0.27 P 0.73 layers lattice-matched to GaAs 0.69 P 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 × 10 16 cm -3 for In 0.37 Ga 0.63 P and 2 × 10 16 cm -3 for In 0.2 Ga 0.8 As 0.27 P 0.73 . Photoluminescence (PL) of the undoped, Te- and Zn-doped In 0.37 Ga 0.63 P and In 0.2 Ga 0.8 As 0.27 P 0.73 layers is described in detail. The emission peaks of 300 and 10 K PL spectra for In 0.37 Ga 0.63 P and In 0.2 Ga 0.8 As 0.27 P 0.73 are 590 and 568 nm and 639 and 615 nm, respectively. The visible light-emitting diodes (LEDs) employing In 0.37 Ga 0.63 P/In 0.2 Ga 0.8 As 0.27 P 0.73 / In 0.37 Ga 0.63 P double heterostructure grown on GaAs 0.69 P 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.