I. Yassievich | Ioffe Physical Technical Institute (original) (raw)

Papers by I. Yassievich

Research paper thumbnail of Resonant States In Modulation Doped Sige Heterostructures As A Source Of Thz Lasing

Towards the First Silicon Laser, 2003

Recent advances in semiconductor lasers considerably extended microelectronic device potentiality... more Recent advances in semiconductor lasers considerably extended microelectronic device potentiality. In particular, significant improvements have been made in output power, stability, and tuneability of different solid state lasers with multiple quantum wells for optical and infrared ranges. A good example is the quantum cascade laser (QCL), which currently can be operated at wavelengths in excess of 10 μm [1]. The lowest frequency achieved now is 24 THz [2]. Recently, first attempts were made to fabricate QCL based on SiGe structures for the THz range (1-10 THz) [3]. However, with the increase of the emission wavelength it becomes more and more difficult to fulfil the various conditions for lasing: the energy band structure, waveguide for radiation propagation in the device, strong phonon absorption, and many other effects which deteriorate laser performance. An alternative type of THz laser source which could utilize a much simpler quantum well (QW) structure is a resonant state laser (RSL), where Ge or another semiconductor with similar band structure is employed. Recently, a tuneable continuous-wave Ge THz laser was realized under the condition of weak external electric field [4].

Research paper thumbnail of Resonant states induced by impurities in heterostructures

Physical Review B, 2002

A study of the formation of resonant states in the conduction band, induced by impurities outside... more A study of the formation of resonant states in the conduction band, induced by impurities outside heterostructure quantum wells, is presented. We derive general expressions for the capture and scattering amplitudes, the resonance position and width, and we also calculate the effect ...

Research paper thumbnail of Deep-level transient spectroscopy study of narrow SiGe quantum wells with high Ge content

Physical review. B, Condensed matter, Jan 15, 1996

Research paper thumbnail of Terahertz Emitters and Detectors Based on SiGe Nanostructures

ABSTRACT Terahertz (THz) electroluminescence was produced by three different types of sources: in... more ABSTRACT Terahertz (THz) electroluminescence was produced by three different types of sources: intersubband transitions in silicon germanium quantum wells, resonant state transitions in boron-doped strained silicon germanium layers, and hydrogenic transitions from dopant atoms in silicon. The devices were grown by molecular beam epitaxy, fabricated by dry etching, and characterized by infrared spectroscopy. The absorption of THz was observed in silicon germanium quantum wells at energies corresponding to heavy hole and light hole intersubband transitions. These results suggest that SiGe nanotechnology is attractive for THz device applications.

Research paper thumbnail of Electroluminescence efficiency of silicon diodes

Physics of the Solid State, 2004

ABSTRACT

Research paper thumbnail of Excitons in Si nanocrystals

Physics of the Solid State, 2004

The states of electron-hole pairs in spherical silicon nanocrystals are theoretically studied usi... more The states of electron-hole pairs in spherical silicon nanocrystals are theoretically studied using the “multiband” effective-mass approximation in the limit of an infinitely high potential barrier at the boundary. The degeneracy of the states at the top of the valence band is taken into account in the spherical approximation, and the ellipsoidal character of the electronic spectrum in the conduction band is allowed for. Coulomb interaction-induced corrections to the energy of an electron-hole pair are found.

Research paper thumbnail of Terahertz-assisted excitation of the 1.5-μm photoluminescence of Er in crystalline Si

Physical Review B, 2004

ABSTRACT We show that the 1.5-μm emission from Si:Er generated by continuous-mode band-to-band op... more ABSTRACT We show that the 1.5-μm emission from Si:Er generated by continuous-mode band-to-band optical excitation can be dramatically enhanced by terahertz radiation from a free-electron laser. The effect is observed at cryogenic temperatures in samples prepared from FZ-Si by high-temperature implantation with Er ions and requires a high density of infrared photons (ℏΩ≈100 meV). Based on experimental characteristics of this effect, we argue that the excitation mechanism responsible for the enhancement is, in this case, different from the previously discussed free-electron-laser-induced optical ionization of trapped carriers. A theoretical model of the energy transfer path is developed. It involves participation of a higher-lying conduction c2 band of the Si host and excitation into the 4I11∕2 second excited state of Er3+ ion. Since formation of the Er-related level is not necessary in this mechanism, it opens a possibility to excite a large fraction of Er3+ ions, including also these which are not linked to a recombination level in the band gap. Possible implications of the proposed model toward realization of a true three-level scheme in Si:Er are pointed out. Finally, further experiments necessary for testing and confirmation of the theoretically developed model are proposed.

Research paper thumbnail of The Effect of Phonon Heating on Photoelectric Phenomena (II)

Physica Status Solidi (b), 1972

ABSTRACT

Research paper thumbnail of Effect of spin–orbit interaction on tunnel ionization of deep centers in electric field

Physica B: Condensed Matter, 2003

ABSTRACT

Research paper thumbnail of Excitation mechanism of erbium photoluminescence in bulk silicon and silicon nanostructures

Materials Science and Engineering: B, 2003

We present a short review of the theoretical and experimental results concerning the problem of e... more We present a short review of the theoretical and experimental results concerning the problem of excitation mechanism of erbium photoluminescence in silicon and silicon nanostructures. The excitation process consists of two stages, the first being absorption of radiation by bulk silicon matrix or nanocrystals while the second is the Auger excitation of erbium ions by recombining electron-hole pairs. The large values of Auger excitation cross-section under optical pumping in semiconductor matrices are due to large values of band-to-band absorption coefficient of bulk silicon or silicon nanocrystals exceeding by several orders of magnitude the absorption coefficient of erbium in dielectric SiO 2 matrix. The specific features of Auger process in silicon nanocrystals when excitation of erbium ions is produced by quantum-confined electron-hole pairs are discussed.

Research paper thumbnail of Enhancement of erbium luminescence in c-Si by terahertz radiation

Materials Science and Engineering: B, 2003

ABSTRACT

Research paper thumbnail of Electron and hole states in ultrathin quantum wells

Journal of Physics: Condensed Matter, 1994

Research paper thumbnail of Effect of a magnetic field on thermally stimulated ionization of impurity centers in semiconductors by submillimeter radiation

Journal of Experimental and Theoretical Physics, 2000

The probability of electron tunneling from a bound state into a free state in crossed ac electric... more The probability of electron tunneling from a bound state into a free state in crossed ac electric and dc magnetic fields is calculated in the quasiclassical approximation. It is shown that a magnetic field decreases the electron tunneling probability. This decreases the probability of thermally activated ionization of deep impurity centers by submillimeter radiation. The logarithm of the ionization probability is a linear function of the squared amplitude of the electric field and increases rapidly with the frequency of the electric field. © 2000 MAIK "Nauka/Interperiodica".

Research paper thumbnail of Trions in silicon nanocrystals in an amorphous hydrogenated silicon matrix

Semiconductors, 2014

ABSTRACT A simple theoretical model of the radiative recombination in amorphous hydrogenated sili... more ABSTRACT A simple theoretical model of the radiative recombination in amorphous hydrogenated silicon films containing silicon nanocrystals is suggested. This material is used for the fabrication of modern thin-film solar cells. The calculation results are in good agreement with experimental data on the photoluminescence spectra.

Research paper thumbnail of Excitation of Er3+ ions in SiO2 with Si nanocrystals

Semiconductors, 2008

ABSTRACT Probabilities of excitation of erbium ions via Coulomb interaction with carriers localiz... more ABSTRACT Probabilities of excitation of erbium ions via Coulomb interaction with carriers localized in silicon nanocrystals embedded in SiO2, in recombination and intraband relaxation of these carriers, have been calculated.

Research paper thumbnail of Light emission from silicon nanocrystals

Semiconductors, 2013

ABSTRACT The main experimental results of studies of the photoluminescence of silicon nanocrystal... more ABSTRACT The main experimental results of studies of the photoluminescence of silicon nanocrystals and theoretical methods developed for the description of optical processes occurring in them are reviewed. Special attention is focused on silicon nanocrystals in the SiO{sub 2} matrix that were the object of most of the studies. Two fundamental theoretical methods described in detail are the multiband effective-mass method and the tight-binding method which have found wide application in simulating various processes occurring in nanostructures. A phenomenological model for excitons self-trapped on the surface of oxidized silicon nanocrystals, which has been recently developed on the basis of experimental results obtained by femtosecond spectroscopy, is reported.

Research paper thumbnail of Mechanisms of excitation and thermal quenching of erbium-ion luminescence in crystalline and amorphous silicon

Physics of the Solid State, 1999

A short review is presented of the erbium-ion excitation mechanisms in crystalline and amorphous ... more A short review is presented of the erbium-ion excitation mechanisms in crystalline and amorphous silicon and of the processes governing thermal quenching of erbium luminescence in these materials, which draws both from the studies carried out by the present authors and from available literature data.

Research paper thumbnail of Erbium-induced interdiffusion of gallium and aluminum in GaAs/AlGaAs quantum-well structures

Physics of the Solid State, 1999

ABSTRACT Incorporation of erbium into GaAs/AlGaAs quantum-well structures in the course of their ... more ABSTRACT Incorporation of erbium into GaAs/AlGaAs quantum-well structures in the course of their MBE growth has been shown experimentally to initiate effective Ga and Al interdiffusion and Er diffusion due to the erbium-induced enhanced vacancy formation. A mechanism for the formation of cation vacancies is proposed, which is based on the generation of local strains by the incorporating erbium. It is shown that erbium interacts with aluminum to produce in AlGaAs aluminum-enriched, erbium-containing clusters.

Research paper thumbnail of Domain formation in films of magnetic nanoparticles with a random distribution of anisotropy axes

Physics of the Solid State, 2007

... [1–5]. A tech-nique for fabricating nickel granular films through laser electrodispersion has... more ... [1–5]. A tech-nique for fabricating nickel granular films through laser electrodispersion has been developed recently at the Ioffe Physicotechnical Institute of the Russian Acad-emy of Sciences (Petersburg, Russia) [6]. The main fea-ture of this technique is that the prepared film ...

Research paper thumbnail of Theoretical modeling of thermally activated luminescence quenching processes in Si:Er

Physical Review B, 2005

ABSTRACT A theoretical description of processes responsible for thermally activated nonradiative ... more ABSTRACT A theoretical description of processes responsible for thermally activated nonradiative relaxation of excited Er3+ ions in Si is developed. Microscopic models for the back transfer mechanism of excitation reversal and for Auger energy transfer to free and localized carriers are proposed. Simulations based on physical parameters are made and reasonable agreement with experiment is obtained. At the same time, the proposed theoretical treatment reveals aspects of the Auger deexcitation. In particular, important differences between interaction with free electrons and free holes are concluded. Experimental support for these findings is pointed out.

Research paper thumbnail of Resonant States In Modulation Doped Sige Heterostructures As A Source Of Thz Lasing

Towards the First Silicon Laser, 2003

Recent advances in semiconductor lasers considerably extended microelectronic device potentiality... more Recent advances in semiconductor lasers considerably extended microelectronic device potentiality. In particular, significant improvements have been made in output power, stability, and tuneability of different solid state lasers with multiple quantum wells for optical and infrared ranges. A good example is the quantum cascade laser (QCL), which currently can be operated at wavelengths in excess of 10 μm [1]. The lowest frequency achieved now is 24 THz [2]. Recently, first attempts were made to fabricate QCL based on SiGe structures for the THz range (1-10 THz) [3]. However, with the increase of the emission wavelength it becomes more and more difficult to fulfil the various conditions for lasing: the energy band structure, waveguide for radiation propagation in the device, strong phonon absorption, and many other effects which deteriorate laser performance. An alternative type of THz laser source which could utilize a much simpler quantum well (QW) structure is a resonant state laser (RSL), where Ge or another semiconductor with similar band structure is employed. Recently, a tuneable continuous-wave Ge THz laser was realized under the condition of weak external electric field [4].

Research paper thumbnail of Resonant states induced by impurities in heterostructures

Physical Review B, 2002

A study of the formation of resonant states in the conduction band, induced by impurities outside... more A study of the formation of resonant states in the conduction band, induced by impurities outside heterostructure quantum wells, is presented. We derive general expressions for the capture and scattering amplitudes, the resonance position and width, and we also calculate the effect ...

Research paper thumbnail of Deep-level transient spectroscopy study of narrow SiGe quantum wells with high Ge content

Physical review. B, Condensed matter, Jan 15, 1996

Research paper thumbnail of Terahertz Emitters and Detectors Based on SiGe Nanostructures

ABSTRACT Terahertz (THz) electroluminescence was produced by three different types of sources: in... more ABSTRACT Terahertz (THz) electroluminescence was produced by three different types of sources: intersubband transitions in silicon germanium quantum wells, resonant state transitions in boron-doped strained silicon germanium layers, and hydrogenic transitions from dopant atoms in silicon. The devices were grown by molecular beam epitaxy, fabricated by dry etching, and characterized by infrared spectroscopy. The absorption of THz was observed in silicon germanium quantum wells at energies corresponding to heavy hole and light hole intersubband transitions. These results suggest that SiGe nanotechnology is attractive for THz device applications.

Research paper thumbnail of Electroluminescence efficiency of silicon diodes

Physics of the Solid State, 2004

ABSTRACT

Research paper thumbnail of Excitons in Si nanocrystals

Physics of the Solid State, 2004

The states of electron-hole pairs in spherical silicon nanocrystals are theoretically studied usi... more The states of electron-hole pairs in spherical silicon nanocrystals are theoretically studied using the “multiband” effective-mass approximation in the limit of an infinitely high potential barrier at the boundary. The degeneracy of the states at the top of the valence band is taken into account in the spherical approximation, and the ellipsoidal character of the electronic spectrum in the conduction band is allowed for. Coulomb interaction-induced corrections to the energy of an electron-hole pair are found.

Research paper thumbnail of Terahertz-assisted excitation of the 1.5-μm photoluminescence of Er in crystalline Si

Physical Review B, 2004

ABSTRACT We show that the 1.5-μm emission from Si:Er generated by continuous-mode band-to-band op... more ABSTRACT We show that the 1.5-μm emission from Si:Er generated by continuous-mode band-to-band optical excitation can be dramatically enhanced by terahertz radiation from a free-electron laser. The effect is observed at cryogenic temperatures in samples prepared from FZ-Si by high-temperature implantation with Er ions and requires a high density of infrared photons (ℏΩ≈100 meV). Based on experimental characteristics of this effect, we argue that the excitation mechanism responsible for the enhancement is, in this case, different from the previously discussed free-electron-laser-induced optical ionization of trapped carriers. A theoretical model of the energy transfer path is developed. It involves participation of a higher-lying conduction c2 band of the Si host and excitation into the 4I11∕2 second excited state of Er3+ ion. Since formation of the Er-related level is not necessary in this mechanism, it opens a possibility to excite a large fraction of Er3+ ions, including also these which are not linked to a recombination level in the band gap. Possible implications of the proposed model toward realization of a true three-level scheme in Si:Er are pointed out. Finally, further experiments necessary for testing and confirmation of the theoretically developed model are proposed.

Research paper thumbnail of The Effect of Phonon Heating on Photoelectric Phenomena (II)

Physica Status Solidi (b), 1972

ABSTRACT

Research paper thumbnail of Effect of spin–orbit interaction on tunnel ionization of deep centers in electric field

Physica B: Condensed Matter, 2003

ABSTRACT

Research paper thumbnail of Excitation mechanism of erbium photoluminescence in bulk silicon and silicon nanostructures

Materials Science and Engineering: B, 2003

We present a short review of the theoretical and experimental results concerning the problem of e... more We present a short review of the theoretical and experimental results concerning the problem of excitation mechanism of erbium photoluminescence in silicon and silicon nanostructures. The excitation process consists of two stages, the first being absorption of radiation by bulk silicon matrix or nanocrystals while the second is the Auger excitation of erbium ions by recombining electron-hole pairs. The large values of Auger excitation cross-section under optical pumping in semiconductor matrices are due to large values of band-to-band absorption coefficient of bulk silicon or silicon nanocrystals exceeding by several orders of magnitude the absorption coefficient of erbium in dielectric SiO 2 matrix. The specific features of Auger process in silicon nanocrystals when excitation of erbium ions is produced by quantum-confined electron-hole pairs are discussed.

Research paper thumbnail of Enhancement of erbium luminescence in c-Si by terahertz radiation

Materials Science and Engineering: B, 2003

ABSTRACT

Research paper thumbnail of Electron and hole states in ultrathin quantum wells

Journal of Physics: Condensed Matter, 1994

Research paper thumbnail of Effect of a magnetic field on thermally stimulated ionization of impurity centers in semiconductors by submillimeter radiation

Journal of Experimental and Theoretical Physics, 2000

The probability of electron tunneling from a bound state into a free state in crossed ac electric... more The probability of electron tunneling from a bound state into a free state in crossed ac electric and dc magnetic fields is calculated in the quasiclassical approximation. It is shown that a magnetic field decreases the electron tunneling probability. This decreases the probability of thermally activated ionization of deep impurity centers by submillimeter radiation. The logarithm of the ionization probability is a linear function of the squared amplitude of the electric field and increases rapidly with the frequency of the electric field. © 2000 MAIK "Nauka/Interperiodica".

Research paper thumbnail of Trions in silicon nanocrystals in an amorphous hydrogenated silicon matrix

Semiconductors, 2014

ABSTRACT A simple theoretical model of the radiative recombination in amorphous hydrogenated sili... more ABSTRACT A simple theoretical model of the radiative recombination in amorphous hydrogenated silicon films containing silicon nanocrystals is suggested. This material is used for the fabrication of modern thin-film solar cells. The calculation results are in good agreement with experimental data on the photoluminescence spectra.

Research paper thumbnail of Excitation of Er3+ ions in SiO2 with Si nanocrystals

Semiconductors, 2008

ABSTRACT Probabilities of excitation of erbium ions via Coulomb interaction with carriers localiz... more ABSTRACT Probabilities of excitation of erbium ions via Coulomb interaction with carriers localized in silicon nanocrystals embedded in SiO2, in recombination and intraband relaxation of these carriers, have been calculated.

Research paper thumbnail of Light emission from silicon nanocrystals

Semiconductors, 2013

ABSTRACT The main experimental results of studies of the photoluminescence of silicon nanocrystal... more ABSTRACT The main experimental results of studies of the photoluminescence of silicon nanocrystals and theoretical methods developed for the description of optical processes occurring in them are reviewed. Special attention is focused on silicon nanocrystals in the SiO{sub 2} matrix that were the object of most of the studies. Two fundamental theoretical methods described in detail are the multiband effective-mass method and the tight-binding method which have found wide application in simulating various processes occurring in nanostructures. A phenomenological model for excitons self-trapped on the surface of oxidized silicon nanocrystals, which has been recently developed on the basis of experimental results obtained by femtosecond spectroscopy, is reported.

Research paper thumbnail of Mechanisms of excitation and thermal quenching of erbium-ion luminescence in crystalline and amorphous silicon

Physics of the Solid State, 1999

A short review is presented of the erbium-ion excitation mechanisms in crystalline and amorphous ... more A short review is presented of the erbium-ion excitation mechanisms in crystalline and amorphous silicon and of the processes governing thermal quenching of erbium luminescence in these materials, which draws both from the studies carried out by the present authors and from available literature data.

Research paper thumbnail of Erbium-induced interdiffusion of gallium and aluminum in GaAs/AlGaAs quantum-well structures

Physics of the Solid State, 1999

ABSTRACT Incorporation of erbium into GaAs/AlGaAs quantum-well structures in the course of their ... more ABSTRACT Incorporation of erbium into GaAs/AlGaAs quantum-well structures in the course of their MBE growth has been shown experimentally to initiate effective Ga and Al interdiffusion and Er diffusion due to the erbium-induced enhanced vacancy formation. A mechanism for the formation of cation vacancies is proposed, which is based on the generation of local strains by the incorporating erbium. It is shown that erbium interacts with aluminum to produce in AlGaAs aluminum-enriched, erbium-containing clusters.

Research paper thumbnail of Domain formation in films of magnetic nanoparticles with a random distribution of anisotropy axes

Physics of the Solid State, 2007

... [1–5]. A tech-nique for fabricating nickel granular films through laser electrodispersion has... more ... [1–5]. A tech-nique for fabricating nickel granular films through laser electrodispersion has been developed recently at the Ioffe Physicotechnical Institute of the Russian Acad-emy of Sciences (Petersburg, Russia) [6]. The main fea-ture of this technique is that the prepared film ...

Research paper thumbnail of Theoretical modeling of thermally activated luminescence quenching processes in Si:Er

Physical Review B, 2005

ABSTRACT A theoretical description of processes responsible for thermally activated nonradiative ... more ABSTRACT A theoretical description of processes responsible for thermally activated nonradiative relaxation of excited Er3+ ions in Si is developed. Microscopic models for the back transfer mechanism of excitation reversal and for Auger energy transfer to free and localized carriers are proposed. Simulations based on physical parameters are made and reasonable agreement with experiment is obtained. At the same time, the proposed theoretical treatment reveals aspects of the Auger deexcitation. In particular, important differences between interaction with free electrons and free holes are concluded. Experimental support for these findings is pointed out.