Structural and electronic properties of doped InP/InGaAs short period superlattices grown by LP-MOVPE

摘要

We have studied the structural and electronic properties of lattice-matched InP/InGaAs superlattices with planar doping with Si in the center of the barrier layers, using X-ray spectroscopy, transport and photoluminescence (PL) measurements. The formation of superlattice minibands can be seen in the Shubnikov-de Haas (SdH) spectra. The PL spectra show an emission band at high energies, which is associated with carriers confined by the superlattice. As the thickness of the barriers was made smaller, the SdH oscillations decreased in frequency and the PL high-energy emission band narrowed, due to a reduction in the density of free carriers. A possible cause for this is the greater probability of the Si atoms being incorporated into acceptor sites, located within the interface layers, in samples with thinner barriers.