Electrical and optical properties of high purity In 0.5Ga 0.5P grown on GaAs by liquid phase epitaxy

Abstract

The growth of high purity In 0.5Ga 0.5P epitaxial layers was carried out by liquid phase epitaxy with a supersaturation temperature of 6° C. The lattice mismatch between the InGaP layer and the GaAs substrate was 0.10% measured by X-ray diffraction. The bandgap and the quality of the epitaxial layers were determined by photoluminescence. The narrowest full width at half maximum of the photoluminescent spectra was 35.0 and 10.6 meV at 300 and 14 K, respectively. Hall and capacitance-coltage measurements show that a net carrier concentration of 3 × 10 15 cm −3 has been achieved, which is by one or two orders of magnitude lower than those previously reported. Forward bias current-voltage measurement of a Au-In 0.5Ga 0.5P Schottky diode shows that the ideality factor n is calculated to be 1.08 and the barrier height φ n is 0.95 eV. This value is rather close to that of 1.02 eV obtained by capacitance-voltage measurements. Deep level traps in the In 0.5Ga 0.5P epitaxial layer were studied by deep level transient spectroscopy. The only thermal activated energy level is located at E c - 0.39 eV and the electron trap concentration is below 2 × 10 14 cm −3.