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Papers by Zakhary Krasilnik
ECS Journal of Solid State Science and Technology, 2022
Near-infrared stimulated emission (SE) from InGaN layers grown by plasma-assisted molecular beam ... more Near-infrared stimulated emission (SE) from InGaN layers grown by plasma-assisted molecular beam epitaxy has been studied, and the influence of the growth temperature (T gr) on the SE threshold has been revealed. The obtained experimental data strongly suggest a two-layer model for the grown InGaN structure with a thin defect-rich interface layer and a relatively pure InGaN bulk responsible for light emission. For the latter, the crystalline quality appears to be unaffected by the growth temperature, at least in terms of free electron concentration, which is supported by the similar spontaneous luminescence intensities measured throughout the entire T gr range of 430 °C–510 °C. However, the quality of the interface layer improves with increasing T gr, leading to a decrease in the SE threshold down to ∼10 kW cm−2 at T = 77 K for the samples grown at T gr = 470 °C–480 °C. For the higher growth temperatures (T gr ≥ 490 °C), the SE threshold increases rapidly with T gr, apparently relat...
Erbium doped silicon single-and multilayer structures for light-emitting device and laser applica... more Erbium doped silicon single-and multilayer structures for light-emitting device and laser applications
Semiconductor Lasers and Laser Dynamics VIII, 2018
A combination of high operation temperatures and small sizes of diode lasers directly grown on si... more A combination of high operation temperatures and small sizes of diode lasers directly grown on silicon substrates is essential for their application in future photonic integrated circuits. In this work, we report on electrically-pumped III-V microdisk lasers monolithically grown on Si substrates with active regions of two kinds: either an InGaAs/GaAs quantum well (QW) or InAs/InGaAs/GaAs quantum dots (QDs). Microdisk resonators were defined using photolithography and plasma chemical etching. The active region diameter was varied from 11 to 31 µm. Microlasers were tested without external cooling at room and elevated temperatures. The QW laser structure was epitaxially grown by MOCVD on silicon (100) with an intermediate MBE-grown Ge buffer. Under pulsed injection (0.5-µs-long injection pulses with 150 Hz repetition rate), lasing is achieved in QW microlasers with diameters of 23-31 µm with a minimal threshold current density of 28 kA/cm^2. Quasi-single mode lasing (SMSR is up to 20 dB) is observed with emission wavelength around 988 nm. To the best of our knowledge, this is the first quantum well electrically-pumped microdisk lasers monolithically deposited on (001)-oriented Si substrate. Quantum wells are typically characterized by high optical gain and high direct modulation bandwidth, which can be important in view of further miniaturization of microlasers and their future application. The sidewall passivation can be helpful to reduce the threshold current. As compared to QWs, quantum dots demonstrate reduced sensitivity to threading dislocations and other crystalline defects as well as to sidewall recombination owing to a suppressed lateral transport of charge carriers which prevents their diffusion towards non-radiate recombination centers. The QD laser structure was directly grown by MBE on Si (001) substrate with 4° offcut to the [011] plane. QD microlasers were tested at room temperature in CW regime with a DC current varied from 0 to 50 mA and at elevated temperatures under CW and pulsed excitation (0.5-µs-long injection pulses with 10 kHz repetition rate). The InAs/InGaAs QDs active region provides the wavelengths in the 1.32–1.35 µm spectral interval. At room temperature, lasing is achieved in microlasers with diameters of 14-30 µm with a minimal threshold current density of 600 A/cm2 (compare with that of 427 A/cm2 in edge-emitting laser). The threshold current density and specific thermal resistance of 0.004 °C×cm^2/mW are comparable to those of high-quality QD microdisk lasers on GaAs substrates. Lasing wavelength demonstrates low sensitivity to current-induced self-heating. Lasing is single mode (SMSR 20 dB) with a dominant mode linewidth as narrow as 30 pm. Under CW excitation lasing sustains up to 60 °C in microlasers with diameter of 30 µm. Because of self-heating, an actual temperature of the active region is close to 100°C. Under pulsed excitation, the maximal lasing temperature is 110°C. To our best knowledge, these are the smallest microlasers on silicon operating at such elevated temperatures ever reported. Up to 90°C lasing proceeds on the ground state optical transition of QDs with wavelength about 1.35 µm. At higher temperatures, lasing wavelength jumps to the excited state transition.
2021 IEEE Photonics Conference (IPC), 2021
Germanium quantum dots are promising but their photoluminescence intensity is still insufficient ... more Germanium quantum dots are promising but their photoluminescence intensity is still insufficient for practical applications. It is demonstrated that their PL in silicon photonic crystal slab can be dramatically enhanced due to the involvement of the bounds states in the continuum into the emission process.
Laser & Photonics Reviews, 2021
Germanium self-assembled nanoislands and quantum dots are very prospective for CMOScompatible opt... more Germanium self-assembled nanoislands and quantum dots are very prospective for CMOScompatible optoelectronic integrated circuits but their luminescence intensity is still insufficient for many practical applications. Here, we demonstrate experimentally that photoluminescence of Ge nanoislands in silicon photonic crystal slab with hexagonal lattice can be dramatically enhanced due to the involvement in the emission process of the bounds states in the continuum. We experimentally demonstrate more than two orders of magnitude peak photoluminescence enhancement and more than one order of magnitude integrated PL enhancement in a photonic crystal slab compared with the non-structured sample area. We theoretically study this effect by the Fourier modal method in the scattering matrix form and demonstrate the appearance of quasi-normal guided modes in our photonic crystal slab. We also describe their symmetry in terms of group theory. Our work paves the way towards a new class of opto-electronic components compatible with silicon technology. Abbreviations BIC-bound state in the continuum DPL-directional photoluminescence FMM-Fourier modal method FW BIC-Friedrich-Wintgen bound state in the continuum µPL-microphotoluminescence PCS-photonic crystal slab PL-photoluminescence SP BIC-symmetry protected bound state in the continuum TE-transverse electric TM-transverse magnetic
2019 IEEE 16th International Conference on Group IV Photonics (GFP), 2019
The strong enhancement of photoluminescence intensity was observed in photonic crystal slabs real... more The strong enhancement of photoluminescence intensity was observed in photonic crystal slabs realized on Si structures with the self-assembled Ge nanoislands. The observed phenomena are described in terms of the nanoislands — photonic crystal modes interaction.
physica status solidi (b), 2019
Interband photoluminescence (PL) and stimulation emission (SE) from HgTe/ HgCdTe quantum well (QW... more Interband photoluminescence (PL) and stimulation emission (SE) from HgTe/ HgCdTe quantum well (QW) heterostructures are studied in 5-20 mm wavelength range in regard to long-wavelength lasing applications. The authors obtain carrier lifetimes using time-resolved photoconductivity measurements and show that the dominating mechanism of carrier recombination changes from the radiative process to the non-radiative one as the bandgap is decreased, limiting the "operating" temperature for SE. The authors suggest that decreasing the QW width should reverse the balance in carrier recombination in favor of radiative processes and demonstrate 75 K improvement in the "operating" temperature in structure with narrower QW. of the band structure of narrow-gap HgTe/ HgCdTe heterostructures on carrier recombination mechanisms. [4] Recently, it was shown that HgCdTe-based QW can provide stimulated emission in the very longwavelength IR, [5] suggesting that such structures can be interesting for longwavelength emitters. At present moment, the best-performing semiconductor sources for far IR range are quantum cascade lasers (QCLs). They demonstrate ultimate figures of merit almost in the entire IR range. [6] The only "blind spot" of QCLs caused by the strong lattice absorption in traditional production materials (GaAs and InP) lies at wavelengths between 20 and 60 μm. InAs-based and Al-free QCLs are tackling this wavelength range from the mid-IR side, [7] while GaN QCLs have been proposed for frequencies above 5 THz. [8] However, interband lasers are also of interest since they are less demanding from the technological viewpoint and allow wavelength tuning with temperature. The cornerstone of effective light emitter, especially in far infrared range (FIR) range, is to suppress the non-radiative recombination, in
Photonics, Devices, and Systems III, 2006
We present here last results on development and research of Si:Er-based light emitting structures... more We present here last results on development and research of Si:Er-based light emitting structures grown with original sublimation molecular beam epitaxy (SMBE) technique. The paper contains a description ofthe experimental facilities. results ofthe light emitting media (Si:Er and Si1Ge:Er) research and device applications.
physica status solidi (c), 2011
... Phys. Lett. 91(2), 021916 (2007). [12] NV Vostokov, Yu. N. Drozdov, ZF Krasil&#x2... more ... Phys. Lett. 91(2), 021916 (2007). [12] NV Vostokov, Yu. N. Drozdov, ZF Krasil'nik, OAKuznetsov, AV Novikov, VA Perevoshchikov, and M. V. Shaleev, Phys. Solid State 47(1), 42 (2005). [13] MV Shaleev, AV Novikov, AN Yablonskiy, OA Kuznetsov, Yu. ...
Journal of Materials Research, 2006
The paper is a brief retrospective review of our contribution to the Si:Er problem in the last de... more The paper is a brief retrospective review of our contribution to the Si:Er problem in the last decade. It contains a description of the experimental facilities, results of the light-emitting media (Si:Er and Si1−xGex:Er) research, and device applications.
IEEE Journal of Selected Topics in Quantum Electronics, 2006
In this paper, an effect of space charge region (SCR) width on Er-related electroluminescence (EL... more In this paper, an effect of space charge region (SCR) width on Er-related electroluminescence (EL) in reverse biased Si:Er-based light-emitting diodes (LEDs) is under investigation. It is concluded that a trivial widening of the SCR in the examined LEDs with triangular and trapezoidal electric field profiles through SCR does not result in a desirable increase in the Er-related EL intensity. The tunnel transit-time diode structure with a complicated electric field profile through SCR is offered to increase the Er-related EL intensity. The difficulties hampering this process in erbium EL from reverse biased LEDs are under discussion. Index Terms-Erbium-doped silicon, impact excitation, light emitting diodes, p-n junction breakdown. I. INTRODUCTION D OPING silicon with rare earth elements including erbium has been considered, so far, as an opportunity to overcome the limitation due to the indirect band gap of silicon and thus to promote wide use of silicon in optoelectronic applications. Erbium when introduced into a silicon matrix is characterized, in its 3+ state, by a radiative intra-4f shell transition 4 I 13/2 → 4 I 15/2 emitting at a wavelength of 1.54 µm (0.81 eV) which falls into the window of maximum transmission for the silica optical fibers. It is rather an attractive feature of Si:Er emitters. The next feature, not of any lesser importance, is the high Er 3+ excitation cross section stimulated by carrier-mediated processes (up to 3 × 10 −15 cm 2 under the excitation of Er 3+ via electron-hole recombination on an Er-related deep defect [1]) as opposed to the direct optical excitation of Er 3+ in dielectric matrixes (1 × 10 −20 cm 2 in SiO 2 [2]). An impact excitation of erbium ions with hot carriers realized in reverse biased p-n junctions was found the most effective at room temperature [3]. Its advantages are connected with both the high excitation cross section (up to 2 × 10 −16 cm 2 at room temperature [4]) and the strong suppression of nonradiative Er 3+ relaxation processes in the space charge region Manuscript
Laser & Photonics Reviews, 2021
ECS Journal of Solid State Science and Technology, 2022
Near-infrared stimulated emission (SE) from InGaN layers grown by plasma-assisted molecular beam ... more Near-infrared stimulated emission (SE) from InGaN layers grown by plasma-assisted molecular beam epitaxy has been studied, and the influence of the growth temperature (T gr) on the SE threshold has been revealed. The obtained experimental data strongly suggest a two-layer model for the grown InGaN structure with a thin defect-rich interface layer and a relatively pure InGaN bulk responsible for light emission. For the latter, the crystalline quality appears to be unaffected by the growth temperature, at least in terms of free electron concentration, which is supported by the similar spontaneous luminescence intensities measured throughout the entire T gr range of 430 °C–510 °C. However, the quality of the interface layer improves with increasing T gr, leading to a decrease in the SE threshold down to ∼10 kW cm−2 at T = 77 K for the samples grown at T gr = 470 °C–480 °C. For the higher growth temperatures (T gr ≥ 490 °C), the SE threshold increases rapidly with T gr, apparently relat...
Erbium doped silicon single-and multilayer structures for light-emitting device and laser applica... more Erbium doped silicon single-and multilayer structures for light-emitting device and laser applications
Semiconductor Lasers and Laser Dynamics VIII, 2018
A combination of high operation temperatures and small sizes of diode lasers directly grown on si... more A combination of high operation temperatures and small sizes of diode lasers directly grown on silicon substrates is essential for their application in future photonic integrated circuits. In this work, we report on electrically-pumped III-V microdisk lasers monolithically grown on Si substrates with active regions of two kinds: either an InGaAs/GaAs quantum well (QW) or InAs/InGaAs/GaAs quantum dots (QDs). Microdisk resonators were defined using photolithography and plasma chemical etching. The active region diameter was varied from 11 to 31 µm. Microlasers were tested without external cooling at room and elevated temperatures. The QW laser structure was epitaxially grown by MOCVD on silicon (100) with an intermediate MBE-grown Ge buffer. Under pulsed injection (0.5-µs-long injection pulses with 150 Hz repetition rate), lasing is achieved in QW microlasers with diameters of 23-31 µm with a minimal threshold current density of 28 kA/cm^2. Quasi-single mode lasing (SMSR is up to 20 dB) is observed with emission wavelength around 988 nm. To the best of our knowledge, this is the first quantum well electrically-pumped microdisk lasers monolithically deposited on (001)-oriented Si substrate. Quantum wells are typically characterized by high optical gain and high direct modulation bandwidth, which can be important in view of further miniaturization of microlasers and their future application. The sidewall passivation can be helpful to reduce the threshold current. As compared to QWs, quantum dots demonstrate reduced sensitivity to threading dislocations and other crystalline defects as well as to sidewall recombination owing to a suppressed lateral transport of charge carriers which prevents their diffusion towards non-radiate recombination centers. The QD laser structure was directly grown by MBE on Si (001) substrate with 4° offcut to the [011] plane. QD microlasers were tested at room temperature in CW regime with a DC current varied from 0 to 50 mA and at elevated temperatures under CW and pulsed excitation (0.5-µs-long injection pulses with 10 kHz repetition rate). The InAs/InGaAs QDs active region provides the wavelengths in the 1.32–1.35 µm spectral interval. At room temperature, lasing is achieved in microlasers with diameters of 14-30 µm with a minimal threshold current density of 600 A/cm2 (compare with that of 427 A/cm2 in edge-emitting laser). The threshold current density and specific thermal resistance of 0.004 °C×cm^2/mW are comparable to those of high-quality QD microdisk lasers on GaAs substrates. Lasing wavelength demonstrates low sensitivity to current-induced self-heating. Lasing is single mode (SMSR 20 dB) with a dominant mode linewidth as narrow as 30 pm. Under CW excitation lasing sustains up to 60 °C in microlasers with diameter of 30 µm. Because of self-heating, an actual temperature of the active region is close to 100°C. Under pulsed excitation, the maximal lasing temperature is 110°C. To our best knowledge, these are the smallest microlasers on silicon operating at such elevated temperatures ever reported. Up to 90°C lasing proceeds on the ground state optical transition of QDs with wavelength about 1.35 µm. At higher temperatures, lasing wavelength jumps to the excited state transition.
2021 IEEE Photonics Conference (IPC), 2021
Germanium quantum dots are promising but their photoluminescence intensity is still insufficient ... more Germanium quantum dots are promising but their photoluminescence intensity is still insufficient for practical applications. It is demonstrated that their PL in silicon photonic crystal slab can be dramatically enhanced due to the involvement of the bounds states in the continuum into the emission process.
Laser & Photonics Reviews, 2021
Germanium self-assembled nanoislands and quantum dots are very prospective for CMOScompatible opt... more Germanium self-assembled nanoislands and quantum dots are very prospective for CMOScompatible optoelectronic integrated circuits but their luminescence intensity is still insufficient for many practical applications. Here, we demonstrate experimentally that photoluminescence of Ge nanoislands in silicon photonic crystal slab with hexagonal lattice can be dramatically enhanced due to the involvement in the emission process of the bounds states in the continuum. We experimentally demonstrate more than two orders of magnitude peak photoluminescence enhancement and more than one order of magnitude integrated PL enhancement in a photonic crystal slab compared with the non-structured sample area. We theoretically study this effect by the Fourier modal method in the scattering matrix form and demonstrate the appearance of quasi-normal guided modes in our photonic crystal slab. We also describe their symmetry in terms of group theory. Our work paves the way towards a new class of opto-electronic components compatible with silicon technology. Abbreviations BIC-bound state in the continuum DPL-directional photoluminescence FMM-Fourier modal method FW BIC-Friedrich-Wintgen bound state in the continuum µPL-microphotoluminescence PCS-photonic crystal slab PL-photoluminescence SP BIC-symmetry protected bound state in the continuum TE-transverse electric TM-transverse magnetic
2019 IEEE 16th International Conference on Group IV Photonics (GFP), 2019
The strong enhancement of photoluminescence intensity was observed in photonic crystal slabs real... more The strong enhancement of photoluminescence intensity was observed in photonic crystal slabs realized on Si structures with the self-assembled Ge nanoislands. The observed phenomena are described in terms of the nanoislands — photonic crystal modes interaction.
physica status solidi (b), 2019
Interband photoluminescence (PL) and stimulation emission (SE) from HgTe/ HgCdTe quantum well (QW... more Interband photoluminescence (PL) and stimulation emission (SE) from HgTe/ HgCdTe quantum well (QW) heterostructures are studied in 5-20 mm wavelength range in regard to long-wavelength lasing applications. The authors obtain carrier lifetimes using time-resolved photoconductivity measurements and show that the dominating mechanism of carrier recombination changes from the radiative process to the non-radiative one as the bandgap is decreased, limiting the "operating" temperature for SE. The authors suggest that decreasing the QW width should reverse the balance in carrier recombination in favor of radiative processes and demonstrate 75 K improvement in the "operating" temperature in structure with narrower QW. of the band structure of narrow-gap HgTe/ HgCdTe heterostructures on carrier recombination mechanisms. [4] Recently, it was shown that HgCdTe-based QW can provide stimulated emission in the very longwavelength IR, [5] suggesting that such structures can be interesting for longwavelength emitters. At present moment, the best-performing semiconductor sources for far IR range are quantum cascade lasers (QCLs). They demonstrate ultimate figures of merit almost in the entire IR range. [6] The only "blind spot" of QCLs caused by the strong lattice absorption in traditional production materials (GaAs and InP) lies at wavelengths between 20 and 60 μm. InAs-based and Al-free QCLs are tackling this wavelength range from the mid-IR side, [7] while GaN QCLs have been proposed for frequencies above 5 THz. [8] However, interband lasers are also of interest since they are less demanding from the technological viewpoint and allow wavelength tuning with temperature. The cornerstone of effective light emitter, especially in far infrared range (FIR) range, is to suppress the non-radiative recombination, in
Photonics, Devices, and Systems III, 2006
We present here last results on development and research of Si:Er-based light emitting structures... more We present here last results on development and research of Si:Er-based light emitting structures grown with original sublimation molecular beam epitaxy (SMBE) technique. The paper contains a description ofthe experimental facilities. results ofthe light emitting media (Si:Er and Si1Ge:Er) research and device applications.
physica status solidi (c), 2011
... Phys. Lett. 91(2), 021916 (2007). [12] NV Vostokov, Yu. N. Drozdov, ZF Krasil&#x2... more ... Phys. Lett. 91(2), 021916 (2007). [12] NV Vostokov, Yu. N. Drozdov, ZF Krasil'nik, OAKuznetsov, AV Novikov, VA Perevoshchikov, and M. V. Shaleev, Phys. Solid State 47(1), 42 (2005). [13] MV Shaleev, AV Novikov, AN Yablonskiy, OA Kuznetsov, Yu. ...
Journal of Materials Research, 2006
The paper is a brief retrospective review of our contribution to the Si:Er problem in the last de... more The paper is a brief retrospective review of our contribution to the Si:Er problem in the last decade. It contains a description of the experimental facilities, results of the light-emitting media (Si:Er and Si1−xGex:Er) research, and device applications.
IEEE Journal of Selected Topics in Quantum Electronics, 2006
In this paper, an effect of space charge region (SCR) width on Er-related electroluminescence (EL... more In this paper, an effect of space charge region (SCR) width on Er-related electroluminescence (EL) in reverse biased Si:Er-based light-emitting diodes (LEDs) is under investigation. It is concluded that a trivial widening of the SCR in the examined LEDs with triangular and trapezoidal electric field profiles through SCR does not result in a desirable increase in the Er-related EL intensity. The tunnel transit-time diode structure with a complicated electric field profile through SCR is offered to increase the Er-related EL intensity. The difficulties hampering this process in erbium EL from reverse biased LEDs are under discussion. Index Terms-Erbium-doped silicon, impact excitation, light emitting diodes, p-n junction breakdown. I. INTRODUCTION D OPING silicon with rare earth elements including erbium has been considered, so far, as an opportunity to overcome the limitation due to the indirect band gap of silicon and thus to promote wide use of silicon in optoelectronic applications. Erbium when introduced into a silicon matrix is characterized, in its 3+ state, by a radiative intra-4f shell transition 4 I 13/2 → 4 I 15/2 emitting at a wavelength of 1.54 µm (0.81 eV) which falls into the window of maximum transmission for the silica optical fibers. It is rather an attractive feature of Si:Er emitters. The next feature, not of any lesser importance, is the high Er 3+ excitation cross section stimulated by carrier-mediated processes (up to 3 × 10 −15 cm 2 under the excitation of Er 3+ via electron-hole recombination on an Er-related deep defect [1]) as opposed to the direct optical excitation of Er 3+ in dielectric matrixes (1 × 10 −20 cm 2 in SiO 2 [2]). An impact excitation of erbium ions with hot carriers realized in reverse biased p-n junctions was found the most effective at room temperature [3]. Its advantages are connected with both the high excitation cross section (up to 2 × 10 −16 cm 2 at room temperature [4]) and the strong suppression of nonradiative Er 3+ relaxation processes in the space charge region Manuscript
Laser & Photonics Reviews, 2021