Excitons and multi-exciton complexes bound to a two-dimensional hole layer at a silicon surface: the Kondo effect, the Coulomb blockade and a negative photoconductivity
✍ Scribed by P.D. Altukhov; E.G. Kuzminov; G.V. Ivanov
- Publisher
- Elsevier Science
- Year
- 1998
- Tongue
- English
- Weight
- 108 KB
- Volume
- 23
- Category
- Article
- ISSN
- 0749-6036
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✦ Synopsis
The recombination radiation line of surface excitons and the recombination radiation line of multi-exciton complexes bound to a two-dimensional hole layer are observed in luminescence spectra of [100] silicon metal-oxide-semiconductor structures at low twodimensional hole density. The circular polarization of these two lines in a transverse magnetic field is defined by the average electron spin. The hole spin contribution to the circular polarization is very small due to Kondo spin correlations of holes in the excitons and complexes and holes in the two-dimensional hole layer. The Coulomb blockade excludes a direct contribution of the complexes to a surface photoconductivity. Moreover, a significant negative photoconductivity of the two-dimensional holes is observed at high excitation levels, presumably as a result of the quantum scattering of the two-dimensional holes by the complexes. A shell model of surface multi-exciton complexes is introduced.