Effect of Growth Temperature on the Luminescence Properties of InP/GaP Short-Period Superlattice Structures

Abstract

The optical properties of InP/GaP short-period superlattice (SPS) structures grown at varioustemperatures from 400oC to 490oC have been investigated by using temperature-dependentphotoluminescence (PL) and emission wavelength-dependent time-resolved PL measurements. The PL peak energy for SPS samples decreases as the growth temperature increases. Thedecreased PL energy of ∼10 meV for the sample grown at 425oC compared to that for400oC-grown sample is due to the CuPt-B type ordering, while the SPS samples grown at460oC and 490oC exhibit the significant reduction of the PL peak energies due to the combinedeffects of the formation of lateral composition modulation (LCM) and CuPt-B type ordering. The SPS samples with LCM structure show the enhanced carrier lifetime due to the spatialseparation of carriers. This study represents that the bandgap energy of InP/GaP SPS structurescan be controlled by varying growth temperature, leading to LCM formation and CuPt-Btype ordering.