Temperature-Dependent Photoluminescence Characteristics of InAs/GaAs Quantum Dots Directly Grown on Si Substrates

The first operation of an electrically pumped 1.3-μm InAs/GaAs quantum-dot laser was previously reported epitaxially grown on Si (100) substrate. Here the direct epitaxial growth condition of 1.3-μm InAs/GaAs quantum on a Si substrate is further investigated using atomic force microscopy, etch pit density and temperature-dependent photoluminescence (PL) measurements. The PL for Si-based InAs/GaAs quantum dots appears to be very sensitive to the initial GaAs nucleation temperature and thickness with strongest room-temperature emission at 400^\circ\!C (170 nm nucleation layer thickness), due to the lower density of defects generated under this growth condition, and stronger carrier confinement within the quantum dots.