XRD rocking curves obtained for epilayers grown on GaAs substrates.
Photoluminescence spectra obtained at for a epilayer as a function of duration of the rapid annealing process (RTA) at . The lines are provided for eye guidance.
Absorption and PL spectra obtained at low temperature for the epilayer thermally annealed at . , , and correspond to the conduction-to-valence subband energy gaps, the excitonic transitions, and their Rydberg energies, respectively. The and subscripts refer to and spin momenta.
PL spectra for the epilayers obtained at .
(Color online) Low-temperature experimental PL data plotted as a function of N composition for pseudomorphically strained GaAsN epilayers. Open circles are data obtained in this work, and solid squares and stars are data taken from Refs. 25 and 36, respectively. Curves are calculated using the band anticrossing model considering the effect of the lattice mismatch.
(Color online) Experimental PL data (, symbols) plotted as a function of N composition for relaxed films with (solid triangles) and partially relaxed GaAsN epilayers (solid circles). A better description of the experimental data is obtained using the modified band anticrossing model (dashed line). Equation (7) in this paper and LDA calculations for bulk system, taken from the Ref. 14 (dotted line), are included. Conventional band anticrossing model (solid line) is also included for comparison.
Structural characteristics of samples studied in this work. The numbers in parentheses represent the uncertainty in the last digit.
Band structure parameters of zinc-blende structure taken from Refs. 33 and 34 and used to calculate the strain induced valence-band splitting in .
Photoluminescence peak position and data calculated using BAC models for all samples studied here.
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