SEMICONDUCTOR STRUCTURES, LOWDIMENSIONAL SYSTEMS, AND QUANTUM PHENOMENA Photoluminescence Line Width of SelfAssembled Ge(Si) Islands Arranged between Strained Si Layers

The effect of variations in the strained Si layer thicknesses, measurement temperature, and optical excitation power on the width of the photoluminescence line produced by selfassembled Ge(Si) nanois� lands, which are grown on relaxed SiGe/Si(001) buffer layers and arranged between strained Si layers, is stud� ied. It is shown that the width of the photoluminescence line related to the Ge(Si) islands can be decreased or increased by varying the thickness of strained Si layers lying above and under the islands. A decrease in the width of the photoluminescence line of the Ge(Si) islands to widths comparable with the width of the photo� luminescence line of quantum dot (QD) structures based on directgap InAs/GaAs semiconductors is attained with consideration of diffusive smearing of the strained Si layer lying above the islands.