A study of the luminescence properties of epitaxial GaP containing atomic N grown by molecular beam epitaxy using NH3 and PH3 as the column V sources was conducted. The 77 K photoluminescence spectra of the N-doped epitaxial GaP showed a continuous redshift, from 5691 Å (2.18 eV) to 6600 Å (1.88 eV), resulted when the N concentration exceeded ∼5–7×1019 cm−3. This energy shift was found to be consistent with energy gap predictions using the dielectric theory of electronegativity for the GaP1−xNx system. The data also indicate that the emission intensity was maximum for N∼1×1020 cm−3, and then monotonically decreases with increasing N content. This is consistent with the formation of an indirect band-gap semiconductor.

The lateral quantum wells formed in vertical (GaAs)n/(InAs)n and (GaP)n/(InP)n short-period superlattices (SPS) grown on nominally (100) InP and GaAs substrates, respectively, have been examined. The strain induced from the deviation of superlattice periodicity from na0 is the major driving force of the lateral modulation of the composition along the [110] direction, where the integer n is the number of monolayers of each binary compound within a period of SPS structure and a0 is the lattice constant of the substrate material. When the deviation of the superlattice periodicity from na0 is larger than ∼4%, both (GaAs)n/(InAs)n and (GaP)n/(InP)n ordered vertical SPS layers were found to have a lateral periodic modulation of composition with periodicities as small as ∼200 Å. This effect is enhanced when n was increased from 1 to 2.

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Noncontact thickness and composition assessment of a strained AlGaAs/AlAs/InGaAs double barrier multiple quantum well structure High optical quality of strained (111)B In0.12Ga0.88As/GaAs and In0.12Ga0.88As/Al0.2Ga0.8As multiple quantum wells

Long-range ordering in a (GaP)2/(InP)2 short-period superlattice and a Ga0.525In0.475P buffer layer grown on a (001)GaAs substrate by gas source molecular beam epitaxy were studied. Transmission electron microscopy and low-temperature cathodoluminesence techniques were used to examine the microstructure of the short-period superlattice and to determine its band-gap energy. The superlattice layer was found to have a [001] long-range ordered structure with a band gap narrowing of about 130 meV, while the Ga0.525In0.475P layer had a 37 meV band-gap narrowing induced by spontaneous long-range ordering in the [111] direction. The ordered superlattice layer was found to have a growth-induced lateral periodic modulation of the composition along the [1̄10] direction. Within the modulating bands, which had a 200 Å periodicity, the In composition was found to vary from 42 to 56% while the Ga correspondingly varied between 58 and 44%.