M. Shimizu

发表

Polarization Characteristics of MOCVD Grown GaAs/GaAlAs CBH Surface Emitting Lasers

F. Koyama, K. Iga, M. Shimizu, 1988 .

Equivalent Circuit Model for a GaN Gate Injection Transistor Bidirectional Switch

T. Tanaka, M. Shimizu, T. Ueda, 2012, IEEE Transactions on Electron Devices.

High quality thin AlN epilayers grown on Si(110) substrates by metal-organic chemical vapor deposition

M. Shimizu, T. Ide, X. Shen, 2017 .

Generation of dislocations from scratches on GaN formed during wafer fabrication and dislocation reactions during homoepitaxial growth

M. Shimizu, Y. Sugawara, Y. Ishikawa, 2021, Japanese Journal of Applied Physics.

Control of the inversion-channel MOS properties by Mg doping in homoepitaxial p-GaN layers

K. Nakagawa, K. Ueno, M. Shimizu, 2017 .

High Breakdown Voltage AlGaN/GaN MIS-HEMT with SiN and TiO2 Gate Insulator

Hiromichi Ohashi, Hajime Okumura, Yoshiki Yano, 2006 .

Impacts of oxidants in atomic layer deposition method on Al2O3/GaN interface properties

N. Taoka, T. Egawa, M. Shimizu, 2017 .

A transient simulation approach to obtaining capacitance–voltage characteristics of GaN MOS capacitors with deep-level traps

K. Fukuda, T. Hashizume, M. Shimizu, 2018 .

Transverse mode analysis for surface emitting laser using beam propagation method

F. Koyama, K. Iga, M. Shimizu, 1991 .

Improvement of AlGaN/GaN Heterostructure Field Effect Transistor Characteristics by Using Two-Step Ohmic Contact Process

M. Shimizu, H. Okumura, T. Ide, 2003 .

Roles of Si Irradiation during the Growth Interruption on GaN Film Qualities in Plasma-Assisted Molecular Beam Epitaxy : Semiconductors

M. Shimizu, H. Okumura, H. Cho, 2002 .

Phase transitions in iron alloys

M. Shimizu, K. Terao, 1981 .

Improvement of fluorescence intensity of nitrogen vacancy centers in self-formed diamond microstructures

M. Shimizu, M. Kondo, J. Yaita, 2015 .

Recess gate AlGaN/GaN HEMTs using overlap gate metal structure

Yoshiki Yano, M. Shimizu, T. Ide, 2010 .

Study on AlGaN/GaN growth on carbonized Si substrate

M. Shimizu, Y. Takanashi, T. Sakamoto, 2013 .

Impact of gate electrode formation process on Al2O3/GaN interface properties and channel mobility

N. Taoka, H. Amano, M. Shimizu, 2021, Applied Physics Express.

Electrical Characterization at Cubic AlN/GaN Heterointerface Grown by Radio‐Frequency Plasma‐Assisted Molecular Beam Epitaxy

M. Shimizu, S. Chichibu, H. Okumura, 2001 .

Growth Temperature Effects of Chemical Vapor Deposition‐Grown Boron Nitride Layer Using B2H6 and NH3

N. Kumagai, M. Shimizu, Toshikazu Yamada, 2020, physica status solidi (b).

Comparative Study of Boron Precursors for Chemical Vapor‐Phase Deposition‐Grown Hexagonal Boron Nitride Thin Films

N. Kumagai, M. Shimizu, Toshikazu Yamada, 2020, physica status solidi (a).

Chemical Vapor Deposition Growth of BN Thin Films Using B2H6 and NH3

N. Kumagai, M. Shimizu, Toshikazu Yamada, 2019, physica status solidi (b).

Stimulated-emission phenomena from InGaN/GaN multiple-quantum wells grown by plasma-assisted molecular-beam epitaxy

M. Shimizu, H. Okumura, X. Shen, 2001 .

Comparison of surface morphologies in GaN films grown by rf-MBE and MOCVD on vicinal sapphire (0001) substrates

M. Shimizu, G. Y. Zhang, H. Okumura, 2009 .

Quality improvement of III-nitride epilayers and their heterostructures grown on vicinal substrates by rf-MBE

M. Shimizu, H. Okumura, H. Matsuhata, 2007 .

Indium Roles on the GaN Surface Studied Directly by Reflection High-Energy Electron Diffraction Observations

M. Shimizu, H. Okumura, X. Shen, 2002 .

Growth and Characterization of InGaN/GaN Multiple Quantum Wells on Ga-Polarity GaN by Plasma-Assisted Molecular Beam Epitaxy

M. Shimizu, H. Okumura, T. Ide, 2001 .

High-quality InGaN/GaN multiple quantum wells grown on Ga-polarity GaN by plasma-assisted molecular-beam epitaxy

M. Shimizu, H. Okumura, T. Ide, 2001 .

Growth and characterizations of AlGaN/GaN heterostructures using multi-AlN buffer layers in plasma-assisted molecular beam epitaxy

M. Shimizu, H. Okumura, T. Ide, 2001 .

Stability of N- and Ga-polarity GaN surfaces during the growth interruption studied by reflection high-energy electron diffraction

M. Shimizu, H. Okumura, T. Ide, 2000 .

Essential Change in Crystal Qualities of GaN Films by Controlling Lattice Polarity in Molecular Beam Epitaxy

M. Shimizu, H. Okumura, T. Ide, 2000 .

Ultrathin silicon oxynitride layer on GaN for dangling-bond-free GaN/insulator interface

N. Taoka, M. Shimizu, T. Yayama, 2018, Scientific Reports.

Electrically pumped mode-locked vertical-cavity semiconductor lasers.

J. Bowers, R. Mirin, M. Shimizu, 1993, Optics letters.

Impact of strain state on the ultrathin AlN/GaN superlattice growth on Si(110) substrates by metalorganic chemical vapor deposition

M. Shimizu, T. Ide, X. Shen, 2017 .

Comparative study of photoluminescence properties obtained from SiO2/GaN and Al2O3/GaN structures

N. Taoka, M. Shimizu, K. Makihara, 2019, Japanese Journal of Applied Physics.

Charge state modulation of nitrogen vacancy centers in diamond by applying a forward voltage across a p–i–n junction

S. Yamasaki, M. Shimizu, M. Hatano, 2016 .

Understanding of frequency dispersion in C-V curves of metal-oxide-semiconductor capacitor with wide-bandgap semiconductor

N. Taoka, T. Egawa, M. Shimizu, 2017 .

A time-dependent Verilog-A compact model for MOS capacitors with interface traps

K. Fukuda, T. Hashizume, M. Shimizu, 2019, Japanese Journal of Applied Physics.

Simulation of GaN MOS capacitance with frequency dispersion and hysteresis

K. Fukuda, T. Hashizume, M. Shimizu, 2017, 2017 International Conference on Simulation of Semiconductor Processes and Devices (SISPAD).

Two-dimensional electron gases induced by polarization charges in AlN/GaN heterostructure grown by plasma-assisted molecular-beam epitaxy

M. Shimizu, H. Okumura, K. Jeganathan, 2003 .

2DEG characteristics of AlN/GaN heterointerface on sapphire substrates grown by plasma-assisted MBE

M. Shimizu, H. Okumura, K. Jeganathan, 2001 .

A low-leakage and reduced current collapse AlGaN/GaN heterojunction field effect transistor with AlOx gate insulator formed by metal-organic chemical vapor deposition

T. Sakurai, K. Akimoto, M. Shimizu, 2008 .

Gate-Length Dependence of DC Characteristics in Submicron-Gate AlGaN/GaN High Electron Mobility Transistors

M. Shimizu, H. Okumura, T. Ide, 2007 .

Advantages of AlN/GaN Metal Insulator Semiconductor Field Effect Transistor using Wet Chemical Etching with Hot Phosphoric Acid

M. Shimizu, H. Okumura, T. Ide, 2001 .

p-Type InGaN Cap Layer for Normally Off Operation in AlGaN/GaN Heterojunction Field Effect Transistors

M. Shimizu, Y. Yano, M. Inada, 2008 .

High Breakdown Voltage AlGaN/GaN MIS-HEMT with SiN and TiO/sub 2/ Gate Insulator

Y. Yamamoto, M. Shimizu, H. Okumura, 2005, 2005 International Semiconductor Device Research Symposium.

Fabrication of submicron active-region-buried GaN hexagonal frustum structures by selective area growth for directional micro-LEDs

N. Kumagai, M. Shimizu, Tokio Takahashi, 2019, Journal of Crystal Growth.

Pulse height defect of low energy ions in surface barrier detectors

M. Shimizu, Y. Oguri, E. Arai, 1991 .

Use of Multiple Pairs of Gain and Saturable Absorber Regions for Semiconductor Optical-Pulse Compressor

M. Shimizu, T. Hasama, S. Mukai, 2000 .

Interface properties of SiO2/GaN structures formed by chemical vapor deposition with remote oxygen plasma mixed with Ar or He

N. Taoka, M. Shimizu, K. Makihara, 2018 .

High thermal stability of abrupt SiO2/GaN interface with low interface state density

N. Taoka, M. Shimizu, K. Makihara, 2017 .

Energy band structure and electrical properties of Ga-oxide/GaN interface formed by remote oxygen plasma

N. Taoka, M. Shimizu, K. Makihara, 2018 .

Thermal resistance of 1.3μm InGaAsP vertical cavity lasers

J. Bowers, M. Shimizu, D. Babic, 1993 .

Importance of growth temperature on achieving lattice-matched and strained InAlN/GaN heterostructure by plasma-assisted molecular beam epitaxy

M. Shimizu, K. Jeganathan, 2014 .

Strain relaxation correlated with the transport properties of AlN/GaN heterostructure grown by plasma-assisted molecular-beam epitaxy

M. Shimizu, H. Okumura, K. Jeganathan, 2003 .

Dynamic characteristics and device degradation of GaN-based vertical-cavity surface-emitting laser with an AlInN/GaN distributed Bragg reflector

N. Takada, M. Shimizu, T. Ide, 2021 .

Electronic Structure and Magnetism of AFe2 Compounds with C14 and C15 Laves Structures

M. Shimizu, K. Terao, 1987 .

Normally‐off operation in AlGaN/GaN/AlGaN double heterojunction field effect transistors

M. Shimizu, H. Okumura, K. Arai, 2007 .

Low on‐resistance AlGaN/GaN HEMTs by reducing gate length and source‐gate length

M. Shimizu, H. Okumura, T. Ide, 2008 .

Low-temperature formation of Ga-oxide/GaN interface with remote oxygen plasma and its interface properties

N. Taoka, M. Shimizu, K. Makihara, 2018 .

High Breakdown Voltage AlGaN/GaN Metal–Insulator–Semiconductor High-Electron-Mobility Transistor with TiO2/SiN Gate Insulator

H. Ohashi, M. Shimizu, H. Okumura, 2007 .

High-quality nanodisk of InGaN/GaN MQWs fabricated by neutral-beam-etching and GaN regrowth: towards directional micro-LED in top-down structure

N. Kumagai, K. Endo, M. Shimizu, 2020, Semiconductor Science and Technology.

Direct measurement of lateral macrostep velocity on an AlN vicinal surface by transmission electron microscopy

M. Shimizu, T. Ide, H. Matsuhata, 2012 .

Nondestructive visualization of threading dislocations in GaN by micro raman mapping

M. Shimizu, M. Tagawa, S. Harada, 2019, Japanese Journal of Applied Physics.

Deep-level traps in lightly Si-doped n-GaN on free-standing m-oriented GaN substrates

M. Shimizu, H. Yamada, H. Yamada, 2018 .

Stabilization of nonvolatile memory operations using GaN/AlN resonant tunneling diodes by reducing structural inhomogeneity

M. Shimizu, Tokio Takahashi, M. Nagase, 2018, Japanese Journal of Applied Physics.

Effects of Spin Fluctuations on the Magnetism of (Fe1−xCox)Si

M. Shimizu, J. Inoue, T. Hattori, 1987 .

Reduction in Buffer Leakage Current with Mn-Doped GaN Buffer Layer Grown by Metal Organic Chemical Vapor Deposition

M. Shimizu, M. Hata, T. Ide, 2013 .

Control of Ga-oxide interlayer growth and Ga diffusion in SiO2/GaN stacks for high-quality GaN-based metal–oxide–semiconductor devices with improved gate dielectric reliability

A. Yoshigoe, M. Shimizu, Heiji Watanabe, 2017 .

Impact of byproducts formed on a 4H–SiC surface on interface state density of Al2O3/4H–SiC(0001) gate stacks

N. Taoka, T. Doi, M. Shimizu, 2020 .

Reduction of radiated emission from resonance coil in GaN wireless power transmission circuit by using Nd–Fe–N magnetic material

N. Takada, M. Shimizu, K. Ozaki, 2019 .

High-Quality Growth of AlN Epitaxial Layer by Plasma-Assisted Molecular-Beam Epitaxy

M. Shimizu, H. Okumura, K. Jeganathan, 2002 .

Characterizations of GaN films and GaN/AlN super-lattice structures grown on vicinal sapphire (0 0 0 1) substrates by RF-MBE

M. Shimizu, H. Okumura, Takuji Yamamoto, 2005 .

Impact of Vicinal Sapphire (0001) Substrates on the High-Quality AlN Films by Plasma-Assisted Molecular Beam Epitaxy

Hajime Okumura, M. Shimizu, H. Okumura, 2003 .

Evaluation of AlGaN/GaN-HFET with HfAlO gate insulator

M. Shimizu, H. Okumura, A. Kinoshita, 2007 .

Continuous Output Beam Steering in Vertical-Cavity Surface-Emitting Lasers with Two p-Type Electrodes by Controlling Injection Current Profile

Toshio Nemoto, Hiroyoshi Yajima, Masanobu Watanabe, 1999 .

Detection of edge component of threading dislocations in GaN by Raman spectroscopy

M. Shimizu, M. Tagawa, S. Harada, 2018 .

Comparison of Electrical Properties of Ni/n‐GaN Schottky Diodes on c‐Plane and m‐Plane GaN Substrates

M. Shimizu, H. Yamada, Tokio Takahashi, 2018 .

Impact of substrate off-angle on the m-plane GaN Schottky diodes

M. Shimizu, H. Yamada, Tokio Takahashi, 2017 .

Local Stability, Dielectric Constant, and Spin Susceptibility of Ferromagnetic Itinerant Electrons

M. Shimizu, Mitsuaki Shimizu, Isao Takahashi, 1970 .

Magnetic Properties of Sinusoidal Spin‐Density Waves by the Band Model

M. Shimizu, 1968 .

Effect of double superlattice interlayers on growth of thick GaN epilayers on Si(110) substrates by metalorganic chemical vapor deposition

M. Shimizu, T. Ide, X. Shen, 2016 .

Mechanisms of the micro-crack generation in an ultra-thin AlN/GaN superlattice structure grown on Si(110) substrates by metalorganic chemical vapor deposition

M. Shimizu, T. Ide, T. Takahashi, 2015 .

Self-generated microcracks in an ultra-thin AlN/GaN superlattice interlayer and their influences on the GaN epilayer grown on Si(110) substrates by metal–organic chemical vapor deposition

M. Shimizu, T. Ide, H. Matsuhata, 2015 .

High‐quality GaN film and AlGaN/GaN HEMT grown on 4‐inch Si(110) substrates by MOCVD using an ultra‐thin AlN/GaN superlattice interlayer

M. Shimizu, T. Ide, X. Shen, 2015 .

Role of an ultra-thin AlN/GaN superlattice interlayer on the strain engineering of GaN films grown on Si(110) and Si(111) substrates by plasma-assisted molecular beam epitaxy

G. Chen, M. Shimizu, T. Ide, 2013 .

Modulation of Strain States in GaN Films by a Thin AlN/GaN Superlattice Interlayer Grown on Si(110) Substrates

M. Shimizu, H. Okumura, T. Ide, 2013 .

Realization of compressively strained GaN films grown on Si(110) substrates by inserting a thin AlN/GaN superlattice interlayer

Tokio Takahashi, M. Shimizu, T. Ide, 2012 .

Polarity control in MBE growth of III-nitrides, and its device application

Toshihide Ide, M. Shimizu, H. Okumura, 2002 .

Near‐Complete Elimination of Size‐Dependent Efficiency Decrease in GaN Micro‐Light‐Emitting Diodes

K. Endo, M. Shimizu, S. Samukawa, 2019, physica status solidi (a).

Nitrogen vacancies as a common element of the green luminescence and nonradiative recombination centers in Mg-implanted GaN layers formed on a GaN substrate

A. Uedono, K. Ueno, M. Shimizu, 2017 .

Femtosecond periodic gain vertical-cavity lasers

J. Bowers, R. Mirin, M. Shimizu, 1993, IEEE Photonics Technology Letters.

Electrical properties of Ni/n-GaN Schottky diodes on freestanding m-plane GaN substrates

Tokio Takahashi, Hisashi Yamada, M. Shimizu, 2017 .

Characterizations of GaN films and AlGaN/GaN heterostructures on vicinal sapphire (0001) substrates grown by MOCVD

M. Shimizu, H. Okumura, B. Shen, 2009 .

Epitaxial growth of GaN films on Si(110) substrates by rf-MBE

M. Shimizu, T. Ide, X. Shen, 2012 .

Reduction in residual impurities in semi-polar 303¯1¯ and 202¯1¯ GaN grown by metalorganic vapor phase epitaxy

M. Shimizu, Toshikazu Yamada, Hisashi Yamada, 2019, Journal of Crystal Growth.

Realization of Ga-polarity GaN films in radio-frequency plasma-assisted molecular beam epitaxy

M. Shimizu, H. Okumura, T. Ide, 2000 .

Determination of edge-component Burgers vector of threading dislocations in GaN crystal by using Raman mapping

M. Shimizu, M. Tagawa, S. Harada, 2018, Applied Physics Express.

Impacts of Al2O3/GaN interface properties on the screening effect and carrier mobility in an inversion layer

N. Taoka, M. Shimizu, Toshikazu Yamada, 2018, Japanese Journal of Applied Physics.

Fabrication and analysis of InAlN/GaN metal–insulator–semiconductor high-electron-mobility transistors based on AlN/GaN superlattice channel

M. Shimizu, Toshikazu Yamada, Tokio Takahashi, 2021, Applied Physics Letters.

Strain states in GaN films grown on Si(111) and Si(110) substrates using a thin AlN/GaN superlattice interlayer

M. Shimizu, T. Ide, X. Shen, 2014 .

Demonstration of Quasi-AlGaN/GaN HFET Using Ultrathin GaN/AlN Superlattices as a Barrier Layer

M. Shimizu, T. Ide, X. Shen, 2010, IEEE Electron Device Letters.

Lattice-matched InAlN/GaN two-dimensional electron gas with high mobility and sheet carrier density by plasma-assisted molecular beam epitaxy

Hajime Okumura, Yoshiki Yano, Nakao Akutsu, 2007 .

High-Quality GaN Layers on c-Plane Sapphire Substrates by Plasma-Assisted Molecular-Beam Epitaxy Using Double-Step AlN Buffer Process

M. Shimizu, H. Okumura, K. Jeganathan, 2002 .

Improvement of film quality using Si-doping in AlGaN/GaN heterostructure grown by plasma-assisted molecular beam epitaxy

M. Shimizu, H. Okumura, K. Jeganathan, 2002 .

GaN Crystal Growth on Sapphire Substrate Using Islandlike GaN Buffer Formed by Repetition of Thin-Layer Low-Temperature Deposition and Annealing in rf-Plasma Molecular Beam Epitaxy

M. Shimizu, H. Okumura, G. Piao, 2004 .

Reduction of dislocations in GaN epilayers using templated three-dimensional coherent nanoislands

M. Shimizu, H. Okumura, K. Jeganathan, 2005 .

High-density self-assembled GaN nanoislands on SiC (0001) by molecular-beam epitaxy

M. Shimizu, H. Okumura, K. Jeganathan, 2005 .

Dynamically stable gallium-induced 3×3-SiC (0001) surface for two-dimensional GaN nucleation by molecular-beam epitaxy

M. Shimizu, H. Okumura, K. Jeganathan, 2004 .

Growth of GaN-HEMT structures using super lattice quasi-AlGaN alloy barriers on vicinal SiC substrates by rf-MBE

M. Shimizu, H. Okumura, X. Shen, 2007 .

The effect of Gallium gallium adsorbate on SiC(0001) surface for GaN by MBE

M. Shimizu, H. Okumura, K. Jeganathan, 2003 .

Ammonia-free high temperature metalorganic vapor phase epitaxy (AFHT-MOVPE): a new approach to high quality AlN growth

M. Shimizu, K. Kojima, H. Okumura, 2018 .

Quantitative Detection of Protein Using a Top-gate Carbon Nanotube Field Effect Transistor

T. Ataka, M. Shimizu, K. Murata, 2007 .

GaN/SiO2 interface that does not create states within the band gap: A theoretical prediction

M. Shimizu, T. Miyazaki, K. Nishio, 2021, Physical Review Materials.

Controlled oxide interlayer for improving reliability of SiO2/GaN MOS devices

A. Yoshigoe, M. Shimizu, Heiji Watanabe, 2019, Japanese Journal of Applied Physics.

Hot Electron Induced Current Collapse in AlGaN/GaN HEMTs

M. Shimizu, H. Okumura, A. Nakajima, 2007 .

Simulation of deep level transient spectroscopy using circuit simulator with deep level trap model implemented by Verilog-A language

K. Fukuda, T. Hashizume, M. Shimizu, 2019, 2019 International Conference on Simulation of Semiconductor Processes and Devices (SISPAD).

Analysis of dislocation line tilt in GaN single crystal by Raman spectroscopy

M. Shimizu, M. Tagawa, S. Harada, 2020, Japanese Journal of Applied Physics.

Fatigue Properties of Nitrided Ti-6Al-4V Alloy

M. Shimizu, K. Kawasaki, T. Chiba, 1991 .

Experimental Demonstration of n- and p-channel GaN-MOSFETs toward Power IC Applications

N. Taoka, M. Shimizu, H. Yamada, 2019, ECS Journal of Solid State Science and Technology.

A Method of Polarization Stabilization in Surface Emitting Lasers

T. Baba, M. Shimizu, T. Mukaihara, 1991 .

Optical properties of cubic InGaN/GaN multiple quantum wells on 3C-SiC substrates by radio-frequency plasma-assisted molecular beam epitaxy

M. Shimizu, Y. Suzuki, S. Chichibu, 2001 .

Improvement of unipolar power device performance using a polarization junction

Kazuhiro Adachi, Hajime Okumura, Akira Nakajima, 2006 .

Lowering of the Schottky barrier height of metal/n-type 4H-SiC contacts using low-work-function metals with thin insulator insertion

T. Doi, M. Shimizu, O. Nakatsuka, 2021 .

Thermodynamics of Phase Transitions in Iron

M. Shimizu, M. Sakoh, 1977, December 16.

Low-temperature formation of Mg/n-type 4H-SiC ohmic contacts with atomically flat interface by lowering of Schottky barrier height

T. Doi, M. Shimizu, K. Kojima, 2021, Applied Physics Express.

Experimental evidence of the existence of multiple charged states at Al2O3/GaN interfaces

N. Taoka, T. Egawa, M. Shimizu, 2019, Semiconductor Science and Technology.

Optimization of GaN Growth with Ga-Polarity by Referring to Surface Reconstruction Reflection High-Energy Electron Diffraction Patterns

M. Shimizu, H. Okumura, T. Ide, 2001 .

Nonvolatile memory operations using intersubband transitions in GaN/AlN resonant tunneling diodes grown on Si(111) substrates

M. Shimizu, Tokio Takahashi, Masanori Nagase, 2024, Journal of Applied Physics.

Enhancement of nonvolatile memory characteristics caused by GaN/AlN resonant tunneling diodes

M. Shimizu, Tokio Takahashi, M. Nagase, 2023, Semiconductor Science and Technology.

Growth and Characterization of GaN/AlN Resonant Tunneling Diodes for High‐Performance Nonvolatile Memory

M. Shimizu, Tokio Takahashi, M. Nagase, 2020, physica status solidi (a).

Switching characteristics of nonvolatile memory using GaN/AlN resonant tunneling diodes

M. Shimizu, Tokio Takahashi, M. Nagase, 2019, Japanese Journal of Applied Physics.

Resistance switching memory operation using the bistability in current–voltage characteristics of GaN/AlN resonant tunneling diodes

M. Shimizu, Tokio Takahashi, M. Nagase, 2016 .

Investigating the bistability characteristics of GaN/AlN resonant tunneling diodes for ultrafast nonvolatile memory

Tokio Takahashi, Masanori Nagase, M. Shimizu, 2015 .

Fabrication and Evaluation of N-Channel GaN Metal–Oxide–Semiconductor Field-Effect Transistors Based on Regrown and Implantation Methods

Huu Trung Nguyen, M. Shimizu, Toshikazu Yamada, 2020, Materials.