Growth study of chemical beam epitaxy of GaNxP1−x using NH3 and tertiarybutylphosphine
Abstract A study in the growth of GaN x P 1 − x epilayers by chemical beam epitaxy using tertiarybutylphosphine (TBP), ammonia (NH 3 ), and elemental Ga or triethylgallium is reported. Monitoring reflection high-energy electron diffraction (RHEED) intensity oscillations, we observe that both group-III- and group-V-induced incorporation rates are increased when NH 3 is introduced into a single cracker with TBP. From the difference in the periods of group-V-induced RHEED intensity oscillations, a 16% N incorporation is expected, but X-ray rocking curve measurement shows only 0.08% N. Using separate TBP and NH 3 crackers results in no enhancement in incorporation rates. We conclude that the cracking efficiency of TBP is increased with NH 3 co-injection.
Yellow–green luminescence from isoelectronic nitrogen centers in GaP grown by molecular‐beam epitaxy
Molecular‐beam‐epitaxial growth of GaP incorporating isoelectronic N traps was achieved through coinjection of NH3 and PH3 which were dissociated into P2 and PN fluxes. The photoluminescence spectrum of a sample with a N concentration of ∼2×1019 cm−3 indicated that the dominant emission wavelength was at 5691 A (2.18 eV), which is characteristic of the nearest‐neighbor pair transition NN1. The spectrum of a sample containing ∼2×1020 cm−3 N atoms also displayed strong NN1 pair luminescence in addition to much stronger emission line at 5846 A (2.121 eV), which is believed to be from a local mode outside the vibrational band. The peak intensity of this local mode was ∼25 times greater than the peak emission of the NN1 line from the lighter doped sample.
Single thin‐active‐layer visible‐spectrum In1−xGaxP1−zAsz heterostructure lasers
Single active‐layer visible‐spectrum In1−xGaxP1−zAsz heterostructure lasers are described that exhibit quantum size effects (QSE) in photoluminescence and by means of diode injection (λ<6300 A). Liquid‐phase epitaxial (LPE) quaternary layers as thin as ∼300 A have been realized. It is demonstrated that single thin‐layer recombination wells (Lz<1000 A) are very effective in the capture and recombination of carriers, even if injection occurs at some distance (a<1 μm) from the thin layer. On the other hand, optical confinement and absorption are weak in diodes with single active layers thin enough to exhibit QSE. This behavior indicates that the type of thin‐active‐layer diodes described here are not optimum as lasers, but may lead to improved light emitters.