Optical properties of InAs quantum dots in a Si matrix

Abstract

We investigate the optical properties of nanoscale InAs quantum dots (QDs) in a Si matrix. At a growth temperature of 400 °C, the deposition of 7 ML InAs leads to the formation of coherent islands with dimensions in the 2–4 nm range. A luminescence band in the 1.3 μm region found exclusively for samples with such InAs QDs exhibits a pronounced excitation density dependence of the peak position and a decay time of 440 ns. The optical properties suggest an indirect type II transition for InAs/Si QDs. The electronic structure of InAs/Si QDs is discussed in view of available band offset information.