Growth and Characterization of InGaP Yellow-Green Light-Emitting Diodes by Liquid-Phase Epitaxy

Abstract

Zn-doped InGaP/Te-doped ZnGaP on n-type GaAsP substrate homostructural light-emitting diodes has been reproducibly fabricated by liquid-phase epitaxy using a supercooling technique. The growth and characterization of Te- and Zn-doped InGaP layers are described. The strongest photoluminescence peak intensity occurs at 1×1018 and 6×1017 cm-3 for electron and hole concentrations, respectively. Diodes fabricated from the p-n homostructure are characterized by current-voltage measurement, electroluminescence, light output power, and external quantum efficiency. A forward-bias turn-on voltage of 1.5 V with an ideality factor of 2.02 and a breakdown voltage as high as 20 V are obtained from the current-voltage measurements. The emission peak wavelength and the full width at half-maximum of electroluminescence are around 5840 Å and 66-55 meV at 20 mA, respectively. The light output power of the uncoated diodes is about 35 µW at a dc current of 100 mA, and an external quantum efficiency of ∼0.02% is observed. The EL spectra are compared to the PL spectra of the Zn-doped InGaP layer at 300 and 50 K.

Luminescence Characterization of In0.12Ga0.88As0.34 P 0.66 Grown on GaAs0.61 P 0.39 Substrates by Liquid‐Phase Epitaxy

“…The FWHM value at 20 mA can be comparable to that of 55 meV (14.5 meV) for In0.32Ga0.68P yellow-green LEDs at 584 nm. 27 The shift of the peak wavelength with increasing injected current is due to joule heating. A light output power of 25 ~W at 20 mA is obtained for the p-n homojunction bare LED, which is corresponding to an external quantum efficiency of 0.06%.…”