Развитие молекулярно-пучковой эпитаксии с плазменной активацией азота для получения AlGaN гетероструктур ультрафиолетовой оптоэлектроники
Совместный семинар отделов оптики и физики кристаллов
| Когда |
2014-07-07 c 13:30 по 14:40 |
|---|---|
| Где | Конфренц-зал главного корпуса |
| Имя | Докладчики: д.ф.-м.н. Жмерик Валентин Николаевич (Центр физики наногетероструктур Физико-технического института им.А.Ф.Иоффе РАН) |
| Участники |
Руководитель семинара: д.ф.-м.н. Волков Н.В. |
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Жмерик Валентин Николаевич
Current affiliation:
• Senior researcher of the group of MBE of advanced optoelectronic heterostructures, Centre of Nanoheterostructures Physics, IOFFE Physical Technical Institute of the Russian Academy of Sciences (IOFFE PTI), Politekhnicheskaya 26, 194021 St.Petersburg, Russia.
Current research interests (2014)
are focused on wide-gap III-nitride semiconductors, including:
• Both theoretical and experimental study of plasma assisted molecular beam epitaxy (PA MBE) of
binary and alloyed compounds in the material system (AlGa)N and related nanostructures for applications in UV-optoelectronics with minimum working wavelength λ=210 nm. The main topics are the following:
- Development of the initial growth stages of (2-3)-μm-thick AlN buffer layer over heteroepitaxial substrates (c-Al2O3, first of all) to decrease threading dislocations densities in the top (active) regions of the heterostructures down to 108-109cm-2;
- Study of the growth kinetics of AlGaN epilayers in the low-temperature (<800°C) environment of PA MBE to achieve both atomically smooth and metal droplet-free surface morphology for these layers. Development of the different pulsed growth techniques including standard Migration Enhanced Epitaxy as well as Metal or Temperature Modulated Epitaxy;
- Study of the self-ordering phenomenon in the AlxGa1-xN layers with high Al content (x>0.6) observed in the growth direction at the metal-rich stoichiometrical conditions of PA MBE;
- Implementation of the pseudomorphic growth of AlxGa1-xN/AlN (x>0.5) heterostructures grown on
c-Al2O3 substrates to suppress transition from transverse electric (TE) polarization to transverse magnetic (TM) polarization as the wavelength decreases;
- Development of the new technique to form AlGaN-based quantum well (QW) structures by using submonolayer digital alloying.
• Development of characterization techniques of the growth of III-N epilayers and nanoheterostructures by PA MBE setup Compact 21T (Riber CA) equipped by HD-25 nitrogen activator (Oxford Appl.Res.). Such analytical tools as RHEED (30kV), laser reflectometry (λ=532nm) and IR-pyrometer (λ=910nm) are used.
• Study of their structural and optical properties of AlGaN layers and realted QW structures by measuring:
- Surface and internal morphologies elucidated by different microscopes (SEM, AFM, TEM and HRTEM, STEM HAADF etc.);
- High resolution X-ray diffraction to evaluate threading dislocations, strain and Al-content in the layers;
- Both cw- and time-resolved UV-photoluminescence spectra with the different (TE-TM) polarization degree within a wide temperature range;
- Optically-pumped stimulated emission spectra within a spectral range of 258-303 nm excited by 4th or 5th harmonics of Nd-YAG laser with the minimum threshold excitation density of ~150 kW/cm2 (for λ=289nm);
- Electron-beam pumped spontaneous UV-C emission with a high intensity;
- Cathodolumenscence spectra and layer’s composition by using electron-probe microanalysis, Raman spectroscopy etc.
Historical research interests include the following area:
• Growth of pure InN, InN-In(Metal) composites, InGaN alloys with high In content (>20%) for the green and red light emitting diodes.
• Application of the plasma-assisted technological processes in the MBE of wide bandgap semiconductors (p-type doping II-VI compounds).
• Study of the different low-pressure gas discharges (DC-, RF-, ECR) and development of the new types of plasma sources for the dry etching of III-V compounds and laser deposition of the thin diamond-like films.
• Research and development of Si-based micro-power devices.
Selected publications:
- V.N. Jmerik, E.V. Lutsenko, S.V. Ivanov, Plasma-assisted molecular beam epitaxy of AlGaN heterostructures for deep-ultraviolet optically pumped lasers, Phys. Stat. Sol. A 210, 439-450 (2013).
- V.N. Jmerik et al., Low-threshold 303 nm lasing in AlGaN-based multiple-quantum well structures with an asymmetric waveguide grown by plasma-assisted molecular beam epitaxy on c-sapphire, Appl. Phys. Lett. 96, 141112 (2010).
- V.N. Jmerik et al., AlGaN quantum well structures for deep UV LEDs grown by plasma-assisted MBE using sub-monolayer digital-alloying technique, J.Crystal Growth 311, 2080-2083 (2009).
- D.V. Nechaev et al., Control of threading dislocation density at the initial growth stage of AlN on c-sapphire in plasma-assisted MBE, J. Crys. Growth 378, 319-323 (2013).
- A.M. Mizerov et al., Growth kinetics of AlxGa1-xN layers (0<x<1) in plasma-assisted molecular beam epitaxy, phys. stat. sol. C 7, 2046-2048, (2010).
- V.N. Jmerik et al., Growth of thick AlN epilayers with droplet-free and atomically smooth surface by plasma-assisted molecular beam epitaxy using laser reflectometry monitoring, J.Crystal Growth 354, 188, (2012).
- A.A Toropov et al., Suppression of the quantum-confined Stark effect in AlxGa1-xN/Al y Ga 1-y N corrugated quantum wells, J. Appl.Phys. 114, 124306 (2013).
- S.V. Ivanov, V.N. Jmerik, InN growth by plasma assisted molecular beam epitaxy, Chapter, Vac. Sci. &Techn., in: Nitrides as seen by the technology, ed. By T. Paskova and B. Monemar, Research Signpost (Kerala, 2002), pp. 369-400.
- S. V. Ivanov et al., Plasma-assisted MBE growth and characterization of InN on sapphire, J. Crystal Growth 269, 1-9 (2004).
- T. V. Shubina et al. , Mie Resonances, Infrared Emission, and the Band Gap of InN, Phys. Rev. Lett. 92, 117407 (2004).
- A. A. Toropov et al., Optically Enhanced Emission of Localized Excitons in InxGa1-xN Films by Coupling to Plasmons in a Gold Nanoparticle, Phys. Rev. Lett. 103, 037403 (2009).
- V.N. Jmerik et al., Plasma-assisted MBE of InGaN epilayers with atomically smooth and nanocolumnar morphology, grown on MOVPE GaN/Al2O3-templates, J. Cryst. Growth 301-302, 469-472 (2007).
- T. A. Komissarova et al., Abnormal magnetic-field dependence of Hall coefficient in InN epilayers, Appl. Phys. Lett. 95, 012107 (2009).
- V. N. Jmerik et al., Electrically Stable p-Type Doping of ZnSe Grown by Molecular Beam Epitaxy with Different Nitrogen Activators, J. Cryst. Growth 1-4, 214-215, (2000).
- V. N. Jmerik et al., Optical Control of Group III and N Flux Intensities in Plasma Assisted MBE with RF Capacitively-Coupled Magnetron Nitrogen Activator, phys. stat. sol. (a), 188, 615-619, (2001).
- V. N. Jmerik et al., Сoaxial rf-magnetron nitrogen activator for GaN MBE growth, Materials Science and Engineering B 59, 60-64, (1999).