scholarly journals Properties of InN layers grown by High Pressure CVD

2006 ◽  
Vol 955 ◽  
Author(s):  
Mustafa Alevli ◽  
Goksel Durkaya ◽  
Ronny Kirste ◽  
Aruna Weesekara ◽  
Unil Perera ◽  
...  
Keyword(s):  
High Pressure ◽  
High Speed ◽  
Growth Parameters ◽  
Free Carrier ◽  
Dielectric Constants ◽  
High Quality ◽  
Group Iii ◽  
High Efficient ◽  
Nitride Alloys ◽  
Group Iii Nitride

ABSTRACTIndium nitride (InN) and indium-rich group III-nitride alloys are promising materials for advanced optoelectronic device applications. Indium-rich alloys, e.g. (Ga1-y-xAlyInx)N will enable the fabrication of high-efficient light emitting diodes tunable in the whole visible spectral region, as well as advanced high speed optoelectronics for optical communication operating. The present limitation in this area is the growth of high quality InN and indium-rich group III-nitride alloys as documented in many controversial reports on the true physical properties of InN. The difficulties arise from the low dissociation temperature of InN that requires an extraordinarily high nitrogen overpressure to stabilize the material up to optimum growth temperatures. We developed a novel “high-pressure chemical vapor deposition” (HPCVD) system, capable to control and analyze the vast different partial pressures of the constituents. Our results show that the chosen HPCVD pathway leads to high-quality single crystalline InN, demonstrating that HPCVD is a viable tool for the growth of indium rich group III nitride alloys. The structural analysis of InN deposited on GaN-sapphire substrate by XRD show single phase InN(0002) peaks with full width half maximum (FWHM) around 400 arcsec. Infrared reflectance spectroscopy is used to analyze the plasmon frequencies, high frequency dielectric constants, the free carrier concentrations and carrier mobilities in these layers. For nominal undoped InN layers, free carrier concentrations in the mid 1019 cm−3 and mobilities around 600 cm−2-V-1-s-1 are observed. Further improvements are expected as the growth parameters are optimized. The explored growth parameters are close to of those employed for GaN growth conditions, which is a major step towards the fabrication of indium rich (Ga1−y−xAlyInx)N alloys and heterostructures.

Properties of InN grown by High-Pressure CVD

2005 ◽  
Vol 892 ◽  
Author(s):  
Mustafa Alevli ◽  
Goksel Durkaya ◽  
Vincent Woods ◽  
Ute Habeck ◽  
Hun Kang ◽  
...  
Keyword(s):  
High Pressure ◽  
Real Time ◽  
High Speed ◽  
Growth Process ◽  
Optical Characterization ◽  
Optoelectronic Device ◽  
Process Conditions ◽  
Major Step ◽  
Group Iii ◽  
Group Iii Nitride

AbstractGroup III-nitride compound semiconductors (e.g. AlN-GaN-InN) have generated considerable interest for use in advanced optoelectronic device structures. The fabrication of multi-tandem solar cells, high-speed optoelectronics and solid state lasers operating at higher energy wavelengths will be made possible using (Ga1-y-xAlyInx)N heterostructures due to their robustness against radiation and the wide spectral application range. To date, the growth of indium rich (In1-xGax)N films and heterostructures remains a challenge, primarily due to the large thermal decomposition pressures in indium rich group III-nitride alloys at the optimum growth temperatures. In order to control the partial pressures during the growth process of InN and related alloys, a unique high-pressure chemical vapor deposition (HPCVD) system with integrated real-time optical monitoring capabilities has been developed. We report initial results on InN layers grown at temperatures as high as ∼850°C with reactor pressures around 15 bar. Such process conditions are a major step towards the fabrication of indium rich group III-nitride heterostructures that are embedded in wide band gap group III-nitrides. Real-time optical characterization techniques are applied in order to study the gas phase kinetics and surface chemistry processes during the growth process.For an ammonia to TMI precursor flow ratio below 500, multiple phases with sharp XRD features are observed. Structural analysis perform by Raman scattering techniques indicates that the E2 high mode improves as NH3:TMI ratio is decreased to below 500. Optical characterization of these InN layers indicates that the absorption edge shifts from down from 1.85 eV to 0.7 eV. This shift seems to be caused by a series of localized absorption centers that appear as the indium to nitrogen stoichiometry varies. This contribution will correlate the process parameters to results obtained by XRD, Raman spectroscopy and optical spectroscopy, in order to assess the InN film properties.

Group III-nitride alloys as photovoltaic materials

2004 ◽  
Author(s):  
Joel W. Ager III ◽  
Junqiao Wu ◽  
Kin M. Yu ◽  
R. E. Jones ◽  
S. X. Li ◽  
...  
Keyword(s):  
Group Iii ◽  
Photovoltaic Materials ◽  
Nitride Alloys ◽  
Group Iii Nitride

Integrated Photonic Circuits in Gallium Nitride and Aluminum Nitride

2014 ◽  
Vol 23 (01n02) ◽  
pp. 1450001 ◽  
Author(s):  
Chi Xiong ◽  
Wolfram Pernice ◽  
Carsten Schuck ◽  
Hong X. Tang
Keyword(s):  
High Speed ◽  
Optical Signal ◽  
Silicon Substrates ◽  
Material System ◽  
Group Iii ◽  
Electro Optic ◽  
New Material ◽  
Nanophotonic Circuits ◽  
Group Iii Nitride ◽  
On Chip

Integrated optics is a promising optical platform both for its enabling role in optical interconnects and applications in on-chip optical signal processing. In this paper, we discuss the use of group III-nitride (GaN, AlN) as a new material system for integrated photonics compatible with silicon substrates. Exploiting their inherent second-order nonlinearity we demonstrate and second, third harmonic generation in GaN nanophotonic circuits and high-speed electro-optic modulation in AlN nanophotonic circuits.

Pressure Dependence of Optical Transitions in In-rich Group III-Nitride Alloys

2003 ◽  
Vol 798 ◽  
Author(s):  
S. X. Li ◽  
J. Wu ◽  
W. Walukiewicz ◽  
W. Shan ◽  
E. E. Haller ◽  
...  
Keyword(s):  
Pressure Dependence ◽  
Pressure Coefficient ◽  
Accurate Method ◽  
Group Iii Nitrides ◽  
Localized States ◽  
Optical Transitions ◽  
Group Iii ◽  
Pressure Coefficients ◽  
Nitride Alloys ◽  
Group Iii Nitride

ABSTRACTThe hydrostatic pressure dependence of the optical transitions in InN, In-rich In1-xGaxN (0 < x < 0.5) and In1-xAlxN (x = 0.25) alloys is studied using diamond anvil cells. The absorption edges and the photoluminescence peaks shift to higher energy with pressure. The pressure coefficient of InN is determined to be 3.0±0.1 meV/kbar. Together with previous experimental results, our data suggest that the pressure coefficients of group-III nitride alloys have only a weak dependence on the alloy composition. Photoluminescence gives much smaller pressure coefficients, which is attributed to emission involving highly localized states. This indicates that photoluminescence might not be an accurate method to study the pressure dependence of the fundamental bandgaps of group III-nitrides.

Renaissance and Progress in Nitride Semiconductors - My Personal History of Nitride Research -

2000 ◽  
Vol 639 ◽  
Author(s):  
Isamu Akasaki
Keyword(s):  
High Speed ◽  
High Performance ◽  
Green Light ◽  
Blue Laser ◽  
Personal History ◽  
Nitride Semiconductors ◽  
Quarter Century ◽  
Group Iii ◽  
History Of ◽  
Group Iii Nitride

ABSTRACTWide bandgap group-III nitride semiconductors are currently experiencing the most exciting development. High brightness blue and green light emitting diodes (LEDs) are commercialized, and UV and blue laser diodes (LDs), high-speed transistors (TRs) and UV photodetectors (PDs) with low dark current, which will be able to operate in harsh environments, have been demonstrated. In this paper, renaissance and progress in crystal growth and conductivity control of nitride semiconductors in the last quarter century are reviewed as the groundwork for all of those high-performance devices. My personal history of nitride research will be also introduced.

scholarly journals Optical phonons and free-carrier effects in MOVPE grown AlxGa1−xN measured by Infrared Ellipsometry

1999 ◽  
Vol 4 (1) ◽  
Author(s):  
M. Schubert ◽  
A. Kasic ◽  
T.E. Tiwald ◽  
J. Off ◽  
B. Kuhn ◽  
...  
Keyword(s):  
Dispersion Model ◽  
Free Carrier ◽  
Model Parameters ◽  
Model Calculations ◽  
Group Iii ◽  
Infrared Ellipsometry ◽  
Mode Behavior ◽  
Novel Approach ◽  
Back Ground ◽  
Group Iii Nitride

We report on the application of infrared spectroscopic ellipsometry (IR-SE) for wavenumbers from 333cm−1 to 1200cm−1 as a novel approach to non-destructive optical characterization of free-carrier and optical phonon properties of group III-nitride heterostructures. Undoped α-GaN, α-AlN, α-AlxGa1−xN (x = 0.17, 0.28, 0.5), and n-type silicon (Si) doped α-GaN layers were grown by metal-organic vapor phase epitaxy (MOVPE) on c-plane sapphire (α-Al2O3). The four-parameter semi-quantum (FPSQ) dielectric lattice-dispersion model and the Drude model for free-carrier response are employed for analysis of the IR-SE data. Model calculations for the ordinary (∈⊥) and extraordinary (∈||) dielectric functions of the heterostructure components provide sensitivity to IR-active phonon frequencies and free-carrier parameters. We observe that the α-AlxGa1−xN layers are unintentionally doped with a back ground free-carrier concentration of 1–4 1018cm−3. The ternary compounds reveal a two-mode behavior in ∈⊥, whereas a one-mode behavior is sufficient to explain the optical response for ∈||. We further provide a precise set of model parameters for calculation of the sapphire infrared dielectric functions which are prerequisites for analysis of infrared spectra of III-nitride heterostructures grown on α-Al2O3.

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