Saturation of optical transitions in quantum dots and wires of porous silicon

✍ Scribed by V. Dneprovskii; N. Gushina; D. Okorokov; V. Karavanskii; E. Dovidenko

• Publisher: Elsevier Science
• Year: 1995
• Tongue: English
• Weight: 251 KB
• Volume: 17
• Category: Article
• ISSN: 0749-6036
• DOI: 10.1006/spmi.1995.1010

✦ Synopsis

The bleaching bands have been observed in the time-resolved nonlinear transmission spectra of porous silicon. The increase of transmission at discrete frequencies has been attributed to a saturation of optical transitions between the energy levels of electrons and holes spatially confined within quasi-zerodimensional (quantum dots) and quasi-one-dimensional (quantum wires) nanostructures. The results of independent measurements using transmission electron microscopy have confirmed the existence of quantum dots and wires of corresponding size. The slowed-down energy relaxation from upper to lower levels of size quantization compared with intraband relaxation in the bulk have been observed in the cooled ((80 \mathrm{~K})) platelets of porous silicon.