Luminescence, laser, and carrier-lifetime behavior of constant-temperature LPE In1− x Ga x P ( x =0.52) grown on (100) GaAs

Photoluminescence and carrier lifetime data are obtained on low-dislocation-density (etch pits ≳ 5 × 103/cm2) n-type In1−x Gax P (x=0.52) epitaxial layers grown on (100) surfaces of GaAs by means of a constant-temperature liquid-phase-epitaxial (CT-LPE) process. These crystals are of exceptional quality and readily lase from 77 to 300 °K. The index dispersion relation (n-λ dn/dλ) is determined from the laser mode spacing Δλ in the temperature range 77–300 °K and indicates that at higher thresholds laser operation shifts toward donor tail states. By means of optical phase shift measurements the carrier lifetime (77°K) is examined as a function of wavelength from the spontaneous regime to well above laser threshold. The lifetime data indicate that there is a correlation between a dip in the lifetime due to stimulated emission and the region of the spectrum where the first laser modes appear. These data, and similar data on p-type crystals, indicate that CT-LPE In1−x Gax P should be very promising for the development of room-temperature visible spectrum lasers.