Resonance Raman scattering by optical phonons in unstrained germanium quantum dots

Talochkin, A. B.; Teys, S. A.; Suprun, S. P.

doi:10.1103/physrevb.72.115416

Cited by 29 publications

(26 citation statements)

References 18 publications

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“…Today we have only some very well elaborated methods for formation of NSs in semiconductors. They are: molecular beam epitaxy (MBE), 6 ion implantation 7 chemical vapor deposition method, 8 and laser ablation 9 with followed by thermal annealing in furnace. A lot of time and high vacuum or special environment, for example, inert gas Ar is needed for nano-crystals growth using these methods.…”

Section: Introductionmentioning

confidence: 99%

Nano-Cones Formation on a Surface of Ge, Si Crystals and Si1−xGex Solid Solution by Laser Radiation

Medvíd¹,

Onufrijevs²,

Lyutovich³

et al. 2011

J. Nanosci. Nanotech.

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The study of self-assembling nano-cones induced by irradiation of nanosecond Nd:YAG laser pulses on a surface of a Si1-xGe(x) solid solution is reported. It is shown that dynamics of nano-cones formation depends on concentration of Ge atoms (x) in Si lattice and on the intensity of laser radiation. Two different processes of nano-cones formation depending on x are observed. The first one-at higher concentration of Ge atoms x = 0.3-0.4 and the second one-at lower concentration of Ge atoms at x = 0.15 take place. At the first stage, similar processes of nano-cones formation occur. It means, at low intensity of laser radiation 1 < 2.0 MW/cm2 Ge atoms drift to the irradiated surface due to Thermo-gradient effect and Ge-rich phase is formed for both concentration ranges. The second stage is different for low and high Ge content ranges. At the higher concentration of Ge atoms and intensity of laser radiation 1 > 2.0 MW/cm2 nano-cones formation takes place by Stransky-Krastanov mode. On the same time, at lower concentration of Ge atoms cones look like "tree ring" growth due to melting of Ge separated islands on the irradiated surface at intensity of laser radiation 1 = 20 MW/cm2.

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Section: Introductionmentioning

confidence: 99%

Nano-Cones Formation on a Surface of Ge, Si Crystals and Si1−xGex Solid Solution by Laser Radiation

Medvíd¹,

Onufrijevs²,

Lyutovich³

et al. 2011

J. Nanosci. Nanotech.

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“…E ∆ + electronic transitions of the QDs can be studied by resonant Raman measurements [13,14]. When the energy of the exciting laser is close to that of the optical transitions, the resonance curve can be tuned by pressure.…”

mentioning

confidence: 99%

Raman scattering of capped and uncapped carbon‐induced Ge dots under hydrostatic pressure

Bernardi

Reparaz

Goñi

et al. 2006

Physica Status Solidi (b)

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We compare results from Raman scattering for both capped and uncapped Ge quantum dots under hydrostatic pressure. The behavior of lattice vibrations and electronic transitions of the quantum dots are affected by the presence or absence of a cap layer. The pressure coefficient obtained for the Ge mode of relaxed, uncapped islands is close to the corresponding value in bulk, whereas it is reduced by ∼ 20% in presence of a Si cap layer. This result can be understood by taking into account the change of the boundary condition imposed to the Ge lattice, which is constrained to match that of the silicon matrix. Measurements of the capped sample exhibit a resonant enhancement which is not appreciable for the uncapped dots. We relate this effect to the different lifetime of electronic states.

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“…Today we have only some very well elaborated methods for formation of nanostructures. They are: molecular beam epitaxy [2], ion implantation [3], and laser ablation [4,5]. Therefore, elaboration of new methods for formation of NSs in Si and Ge is a very important task for nano-electronics and optoelectronics, because Si is the basic material in microelectronics, it is cheep and the technology is very well developed.…”

mentioning

confidence: 99%

Quantum confinement effect in nanohills formed on a surface of Ge by laser radiation

Medvíd¹,

Dmytruk

Onufrijevs

et al. 2007

Phys. Status Solidi (c)

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Photoluminescence in visible range of spectra from nanohills formed on a surface of Ge single crystal by JAG:Nd laser radiation was found. This photoluminescence is explained by quantum confinement effect in quantum dots on a top of nanohills. Red shift of 300 cm -1 line micro-Raman back scattering spectrum is an evidence of this suggestion. The calculation of QDs diameter using band gap shift photoluminescence spectra and peak frequency in micro-Raman spectra as a function of diameter for spherical Ge particles gives diameters of nano-balls on the top of nanohills is 4 nm and 6 nm.

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Resonance Raman scattering by optical phonons in unstrained germanium quantum dots

Cited by 29 publications

References 18 publications

Nano-Cones Formation on a Surface of Ge, Si Crystals and Si<SUB>1−<I>x</I></SUB>Ge<SUB><I>x</I></SUB> Solid Solution by Laser Radiation

Nano-Cones Formation on a Surface of Ge, Si Crystals and Si<SUB>1−<I>x</I></SUB>Ge<SUB><I>x</I></SUB> Solid Solution by Laser Radiation

Raman scattering of capped and uncapped carbon‐induced Ge dots under hydrostatic pressure

Quantum confinement effect in nanohills formed on a surface of Ge by laser radiation

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