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- Kaniewska, M., et al.
(författare)
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Hole emission mechanism in Ge/Si quantum dots
- 2011
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Ingår i: Physica Status Solidi (C) Current Topics in Solid State Physics. - : Wiley. - 1610-1642 .- 1862-6351. ; 8:2, s. 411 -413
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Tidskriftsartikel (refereegranskat)abstract
- The mechanisms determining emission of holes in self-assembled Ge quantum dots (QDs) embedded in the p-type Si matrix have been investigated. Specimens were prepared by molecular beam epitaxy (MBE). Electrical methods such as deep level transient spectroscopy (DLTS) and capacitance versus voltage (C-V) measurements were used for the study. The emission mechanisms were identified by measuring a QD-related signal as a function of the repetition frequency of the filling pulses with the reverse voltage and the pulse voltage as a parameter. An observed shift of the signal position or its absence versus the voltage parameters was interpreted in terms of thermal, tunnelling and mixed processes and attributed to the presence of a Coulomb barrier formed as a result of the charging effect. Thermal emission properties of the QDs were characterized under such measurement conditions that tunnelling contributions to the DLTS spectra could be neglected.
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| 2. |
- Kaniewska, M., et al.
(författare)
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Spatial variarion of hole eigen energies in Ge/Si quantum wells
- 2011
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Ingår i: AIP Conference Proceedings. - : AIP. - 1551-7616 .- 0094-243X. - 9780735410022 ; 1399, s. 293-294
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Konferensbidrag (refereegranskat)abstract
- Ge quantum well (QW) structures were prepared through Si-capping of 3.3 ML of Ge by MBE on p +-(001) Si substrates at a growth temperature of 550°C. The spatial variation of hole eigen energies in the QW were revealed by DLTS. Depending on the position on the wafer surface, the hole emission may be imposed by a lateral quantum confinement effect. Results of a study by HRTEM methods demonstrate pronounced fluctuations of the QW thickness and variations of the strain field in the QW.
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| 3. |
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