[17p-PB06-1~3] 13.6 Nanostructures, quantum phenomena, and nano quantum devices

▲ [17p-PB06-3] Abnormal Temperature Dependence of Photoluminescence Properties of In-Plane Ultrahigh-Density InAs/InAsSb Quantum-Dot Layer

〇(D)SIMJUI OON¹, Naoya Miyashita¹, Koichi Yamaguchi¹ (1.UEC Tokyo)

Keywords:quantum dot, photoluminescence

InAs low density Quantum Dots (LD QDs) on InAs wetting layer (WL) with QD densities of 4×10¹⁰ cm^-2 and InAs ultrahigh-density (UHD) QDs on InAsSb WL with QD density of 1×10¹² cm^-2, were fabricated on a GaAs (001) substrate, by using MBE. The focus is on analyzing the temperature dependence of PL minimum energy, which showed the strong coupling properties in the InAs/InAsSb UHD QDs layer. In two temperature ranges of 15 - 100 K and 200 - 250 K, the PL minimum energy of UHD QDs were fitted along the upper and lower Varshni curves, respectively. Between 100 K and 200 K, the PL minimum energy decreased significantly with increasing temperature, shifting from the upper Varshni curve to the lower curve. In addition, PL FWHM were also analyzed in UHD QDs, to determine the carrier distribution behavior affected by thermal. A sudden decrease at 30 - 120 K was observed in FWHM of UHD QDs, due to the carrier escape, and the FWHM remained almost constant at 130 – 200 K, then increased slightly above ~ 200 K. This anomalous phenomenon for UHD QDs could be explained by the in-plane miniband formation due to the strong coupling of neighboring QDs.The variations in PL width were compared with the LD QDs and other references.