Optical properties of InAs quantum dots in a Si matrix

We investigate the optical properties of nanoscale InAs quantum dots (QDs) in a Si matrix. At a growth temperature of 400 degrees 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 mu m 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. (C) 1999 American Institute of Physics. [S0003-6951(99)00512-4].