Article
Crystallography
Theresa E. Saenz, Manali Nandy, Agnieszka Paszuk, David Ostheimer, Juliane Koch, William E. McMahon, Jeramy D. Zimmerman, Thomas Hannappel, Emily L. Warren
Summary: By studying the surface structure and chemical composition of V-groove Si, it is found that different pretreatment methods can be used to deoxidize and clean the V-groove Si surface, demonstrating that the behavior of V-groove Si is similar to that of reference samples of planar Si surfaces, providing a basis for future studies.
JOURNAL OF CRYSTAL GROWTH
(2022)
Article
Crystallography
Enrico Brugnolotto, Markus Scherrer, Heinz Schmid, Vihar Georgiev, Marilyne Sousa
Summary: Template assisted selective epitaxy (TASE) is a promising technique for integrating III-V semiconductors on Si, providing reduced defect density and versatility in fabricating electronic and photonic devices. This study demonstrates the control of composition and morphology of InGaAs quantum wells embedded in a horizontal InP nanowire grown directly on Si, as well as the characterization of heterointerfaces. By varying the precursor switching sequence and utilizing scanning transmission electron microscopy and energy dispersive X-ray spectroscopy, a type I superlattice enclosed in a silicon oxide template was successfully created and analyzed.
JOURNAL OF CRYSTAL GROWTH
(2023)
Article
Crystallography
J. E. Ruiz, D. Lackner, P. L. Souza, F. Dimroth, J. Ohlmann
Summary: The growth of dilute nitrides with metal organic chemical vapor phase epitaxy (MOVPE) faces challenges of low N-incorporation and high impurity levels of carbon and hydrogen. Investigation into N and C-incorporation in GaNxAs1-x showed that N-incorporation is proportional to the N/As ratio, while C primarily comes from group-III-methyl groups.
JOURNAL OF CRYSTAL GROWTH
(2021)
Article
Crystallography
Dadi Wang, Zhibin Liu, Yanan Guo, Jianchang Yan, Jinmin Li, Junxi Wang
Summary: In this study, a silane-pretreatment method was developed to improve the growth mode and crystalline quality of n-Al0.6Ga0.4N on a high-temperature-annealing AlN/sapphire template. The use of SiH4 pretreatment disrupted the pseudo-crystal epitaxy of n-Al0.6Ga0.4N, resulting in 3D growth at the AlGaN/AlN interface. This method also led to a significant reduction in threading dislocations density and paves the way for the preparation and improvement of efficient deep ultraviolet emitters.
JOURNAL OF CRYSTAL GROWTH
(2023)
Article
Crystallography
Kazutada Ikenaga, Nami Tanaka, Taro Nishimura, Hirotaka Iino, Ken Goto, Masato Ishikawa, Hideaki Machida, Tomo Ueno, Yoshinao Kumagai
Summary: The effect of high temperature homoepitaxial growth of (010) beta-Ga2O3 layer by low pressure hot-wall metal-organic vapor phase epitaxy was investigated. The growth rate decreased and the growth mode changed as the growth temperature increased. A smooth, twin-free single-crystalline homoepitaxial layer with a structural quality equivalent to that of the substrate could be grown at 1000 degrees C. The grown layers were all n-type and showed an effective donor concentration approximately equal to the Si impurity concentration.
JOURNAL OF CRYSTAL GROWTH
(2022)
Article
Engineering, Electrical & Electronic
A. Azizur Rahman, Nirupam Hatui, Carina B. Maliakkal, Priti Gupta, Jayesh B. Parmar, Bhagyashree A. Chalke, Arnab Bhattacharya
Summary: The study found that the choice of nucleation layer significantly affects the properties of semipolar GaN epilayers. Direct growth of (112 over bar 2) GaN without buffer layers provided the best crystal quality and relatively enhanced near-band-edge photoluminescence emission.
JOURNAL OF ELECTRONIC MATERIALS
(2021)
Article
Crystallography
Toru Akiyama, Takumi Ohka, Katsuya Nagai, Tomonori Ito
Summary: Through ab initio electronic structure calculations, a systematic investigation of the adsorption behavior of Al and N adatoms on vicinal AlN (0001) surface under metal-organic vapor phase epitaxy (MOVPE) growth conditions was conducted. It was found that the vicinal surface with hydrogen-terminated N atom and NH2 was the most stable under N-rich conditions, while the surface with hydrogen-terminated N atom and NH2 at the step edge was favorable over a wide range of Al chemical potential. The adsorption energy of Al adatoms at the step edge was much lower than that in the terrace region, indicating easier incorporation of Al adatoms into the step edge.
JOURNAL OF CRYSTAL GROWTH
(2021)
Article
Crystallography
Lin Zhang, Zeren Wang, Jiejun Wu, Tong Han, Fang Liu, Xingyu Zhu, Tongjun Yu
Summary: In this study, high quality semi-polar GaN layers were fabricated on m-plane sapphire templates using vertical hydride vapor phase epitaxy system. The in-plane epitaxial relationships between GaN and sapphire substrate were determined, and the crystalline anisotropies were shown to be associated with crystal quality and surface defects.
JOURNAL OF CRYSTAL GROWTH
(2022)
Article
Crystallography
Marzieh Bakhtiary-Noodeh, Theeradetch Detchprohm, Russell D. Dupuis
Summary: This study aims to investigate the unintentional impurity incorporation in GaN epitaxial layers and optimize the growth conditions to reduce background impurity concentrations. The results show that the unintentional incorporation of carbon and silicon impurities is highly dependent on the growth parameters. The use of TEG precursor can reduce the carbon concentration, while the lowest concentration can be achieved with TMG precursor under optimized conditions. Similarly, the lowest background silicon concentration can be achieved with TMG precursor under specific conditions.
JOURNAL OF CRYSTAL GROWTH
(2023)
Article
Nanoscience & Nanotechnology
Katarzyna Ludwiczak, Aleksandra Krystyna Dabrowska, Johannes Binder, Mateusz Tokarczyk, Jakub Iwanski, Boguslawa Kurowska, Jakub Turczynski, Grzegorz Kowalski, Rafal Bozek, Roman Stepniewski, Wojciech Pacuski, Andrzej Wysmolek
Summary: Transition metal dichalcogenides (TMDs) are materials with intriguing optical properties, especially when thinned down to a monolayer. By transferring TMD onto hexagonal boron nitride (hBN), significant improvements in optical and electrical properties can be achieved. A new epitaxial technique has been developed to directly grow high optical quality MoSe2 on an entire 2-inch wafer.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Crystallography
C. R. Tait, S. R. Lee, J. Deitz, M. A. Rodriguez, D. L. Alliman, B. P. Gunning, G. M. Peake, A. Sandoval, N. R. Valdez, P. R. Sharps
Summary: Progress has been made in the synthesis of semimetal Cd3As2 by metal-organic chemical-vapor deposition (MOCVD), with optimized growth conditions revealing that InAs-terminated substrates yield the most desirable results. Advanced imaging techniques and x-ray diffraction modalities have been utilized to extensively study the microstructure of Cd3As2 thin films, showing smooth and specular surfaces with low roughness. The films exhibit strain relaxation and belong to the P4(2)/nbc space group, positioning MOCVD-grown Cd3As2 as a Dirac semimetal of interest for topological quantum materials research.
JOURNAL OF CRYSTAL GROWTH
(2021)
Article
Crystallography
Atsushi Yamada, Junya Yaita, Norikazu Nakamura, Junji Kotani
Summary: The research demonstrates that low-sheet-resistance HEMTs can be achieved by using a strain-controlled high-Al-composition AlGaN barrier. It was found that growing an AlGaN barrier with nitrogen as a carrier gas increases dislocation density and reduces strain, leading to improved electron mobility. Additionally, the use of an AlN spacer helps prevent dislocation and impurity scattering, resulting in successful fabrication of low-sheet-resistance HEMT structures with high Al composition.
JOURNAL OF CRYSTAL GROWTH
(2021)
Article
Crystallography
Takashi Matsuoka, Toshitsugu Mitate, Seiichiro Mizuno, Hiroko Takahata, Tomoyuki Tanikawa
Summary: This paper reviews the current status of N-polar epitaxial growth in our lab, focusing on the growth mechanism of N-polar GaN on sapphire substrate using transmission electron microscopy. Furthermore, it describes the potential device applications including solar cells, red LEDs, and inverted HEMT.
JOURNAL OF CRYSTAL GROWTH
(2023)
Article
Chemistry, Multidisciplinary
Hua-Chiang Wen, Ssu-Kuan Wu, Cheng-Wei Liu, Jin-Ji Dai, Wu-Ching Chou
Summary: The nanotribological properties of AlxGa1-xN epitaxial films grown on low-temperature-grown GaN/AlN/Si substrates were investigated. It was found that the Al compositions played a crucial role in determining the strength of bonding forces and shear resistance. The measured friction coefficient (mu) values decreased with increasing Al compositions, indicating a transition from brittleness to ductility in the AlxGa1-xN system.
Article
Crystallography
Cheyenne Lynsky, Ryan C. White, Yi Chao Chow, Wan Ying Ho, Shuji Nakamura, Steven P. DenBaars, James S. Speck
Summary: The role of V-defect density on the performance of green III-nitride LEDs grown on sapphire substrates was experimentally investigated in this study. Results showed that V-defect engineering has the potential to achieve low forward voltage and long wavelength LEDs on sapphire substrates.
JOURNAL OF CRYSTAL GROWTH
(2021)
Article
Computer Science, Information Systems
Nirupam Hatui, Athith Krishna, Shubhra S. Pasayat, Stacia Keller, Umesh K. Mishra
Summary: Hillock-free thick InGaN layers were successfully grown on N-polar GaN on sapphire by introducing Mg as an additional surfactant and optimizing the H-2 pulse time. Despite adversely affecting In incorporation, Mg enabled the maintenance of good surface morphology while decreasing growth temperature, resulting in a net increase in In composition. The parameter space of growth temperature and Mg precursor flow for obtaining hillock-free epilayers was mapped out.
Article
Physics, Applied
Caroline E. Reilly, Nirupam Hatui, Thomas E. Mates, Shuji Nakamura, Steven P. DenBaars, Stacia Keller
Summary: This research explores the growth of AlN at temperatures below 550 degrees C via MOCVD using a flow-modulated epitaxy scheme, investigating the morphological, compositional, and electronic properties of the films. The study reveals high sheet charges and mobilities for two dimensional electron gases formed at the interface between the low temperature grown AlN layers and the high temperature deposited semi-insulating GaN base layers. Despite low growth temperatures, unintentional gallium incorporation is observed in nominally pure AlN barrier layers near the GaN interface. These results pave the way for the integration of nitride-based electronics on temperature sensitive substrates via epitaxy-based schemes.
APPLIED PHYSICS LETTERS
(2021)
Article
Engineering, Electrical & Electronic
A. Azizur Rahman, Nirupam Hatui, Carina B. Maliakkal, Priti Gupta, Jayesh B. Parmar, Bhagyashree A. Chalke, Arnab Bhattacharya
Summary: The study found that the choice of nucleation layer significantly affects the properties of semipolar GaN epilayers. Direct growth of (112 over bar 2) GaN without buffer layers provided the best crystal quality and relatively enhanced near-band-edge photoluminescence emission.
JOURNAL OF ELECTRONIC MATERIALS
(2021)
Article
Physics, Applied
Christian Wurm, Henry Collins, Nirupam Hatui, Weiyi Li, Shubhra Pasayat, Robert Hamwey, Kai Sun, Islam Sayed, Kamruzzaman Khan, Elaheh Ahmadi, Stacia Keller, Umesh Mishra
Summary: This study demonstrates the achievement of high-quality and relaxed InGaN substrates by growing on a GaN-on-porous GaN pseudo-substrate. Thicker films with higher In composition and smooth surface morphology can be achieved, making them suitable for III-nitride based optoelectronics.
JOURNAL OF APPLIED PHYSICS
(2022)
Article
Physics, Applied
Athith Krishna, Aditya Raj, Nirupam Hatui, Stacia Keller, Steven Denbaars, Umesh K. Mishra
Summary: This study experimentally demonstrates the existence of acceptor traps acting as the source of holes in N-polar p-type modulation doped GaN/(AlN/AlGaN) superlattices. The ionization of acceptor traps explains the higher measured hole concentration compared to the dopants used during growth. The study also provides evidence for the charge-balance in systems showing p-type behavior without sufficient doping.
APPLIED PHYSICS LETTERS
(2022)
Article
Crystallography
Athith Krishna, Aditya Raj, Nirupam Hatui, Stacia Keller, Umesh K. Mishra
Summary: The shortcomings in acceptors of p-type III-nitride semiconductors have resulted in limited research on p-channel electronic devices. This study experimentally demonstrates the presence of acceptor-like traps in Ga-polar p-type uniformly doped (AlGaN/AlN)/GaN SLs with limited Mg doping, acting as the primary source of holes.
Article
Materials Science, Multidisciplinary
A. Azizur Rahman, Arnab Bhattacharya, Arun Sarma
Summary: Cu-Sb-X (X = S, Se, Te) based ternary chalcogenide semiconductors, including Cu3SbS4, Cu3SbSe4, and CuSbTe2, were successfully synthesized by a two-stage process. The synthesized thin films exhibited good crystallinity and optical properties, as confirmed by x-ray diffraction, elemental analyses, scanning electron microscopy, optical spectroscopy, and Raman spectroscopy.
Article
Materials Science, Multidisciplinary
Ajinkya Punjal, Shraddha Choudhary, Maneesha Narayanan, Dhanashree Chemate, Ruta Kulkarni, Arumugam Thamizhavel, Arnab Bhattacharya, S. S. Prabhu
Summary: The terahertz optical properties of vanadium-doped beta-Ga2O3 were studied using terahertz time-domain spectroscopy, showing strong birefringence in the 0.2-2.4 THz range and acting as both a quarter-waveplate and a half-waveplate at specific frequencies.
OPTICAL MATERIALS EXPRESS
(2022)
Article
Crystallography
Nirupam Hatui, Henry Collins, Emmanuel Kayede, Shubhra S. Pasayat, Weiyi Li, Stacia Keller, Umesh K. Mishra
Summary: In this study, fully relaxed and crack-free AlxGa1-xN layers with high Al composition were demonstrated on pseudo-substrates. The growth conditions not only allowed for high quality films, but also suppressed sidewall growth.
Article
Engineering, Electrical & Electronic
Aditya Raj, Athith Krishna, Brian Romanczyk, Nirupam Hatui, Wenjian Liu, Stacia Keller, Umesh K. Mishra
Summary: In this study, a normally-off hole channel FinFET device based on GaN/AlGaN superlattice is reported. By combining Schottky gate with 60 nm wide fins, enhancement mode operation is achieved. The device has an on-current of 13 mA/mm and an on-resistance of 300 Omega.mm. Simultaneously, a large I-on/I-off ratio (>10^7) and a current modulation of more than two orders of magnitude in the enhancement mode regime are also achieved.
IEEE ELECTRON DEVICE LETTERS
(2023)
Article
Engineering, Electrical & Electronic
Weiyi Li, Brian Romanczyk, Matthew Guidry, Emre Akso, Nirupam Hatui, Christian Wurm, Wenjian Liu, Pawana Shrestha, Henry Collins, Christopher Clymore, Stacia Keller, Umesh K. Mishra
Summary: This article presents breakthrough N-polar GaN-on-sapphire deep-recess metal-insulator-semiconductor (MIS)-high-electron-mobility transistors (HEMTs) with outstanding performance at W-band. The use of a thin GaN cap layer, atomic layer deposition (ALD) ruthenium (Ru) gate metallization, and high-quality GaN-on-sapphire epitaxy contributes to the excellent power performance achieved. The N-polar GaN-on-sapphire technology shows great potential for millimeter-wave power amplifier applications with high efficiency and power density.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2023)
Article
Engineering, Electrical & Electronic
Emre Akso, Henry Collins, Christopher Clymore, Weiyi Li, Matthew Guidry, Brian Romanczyk, Christian Wurm, Wenjian Liu, Nirupam Hatui, Robert Hamwey, Pawana Shrestha, Stacia Keller, Umesh K. Mishra
Summary: This study presents a N-polar GaN high-electron-mobility transistor (HEMT) with an outstanding large signal performance at 94 GHz. The device demonstrates a record output power of 712 mW (7.1 W/mm) with 31.7% power-added efficiency (PAE). The study also explores the design considerations for multifinger devices and the best gain performance for > 1 W. The results show the great potential of multifinger N-polar GaN HEMT technology for state-of-the-art W-band power amplifiers.
IEEE MICROWAVE AND WIRELESS TECHNOLOGY LETTERS
(2023)
Proceedings Paper
Engineering, Electrical & Electronic
Matthew Guidry, Pawana Shrestha, Wenjian Liu, Brian Romanczyk, Nirupam Hatui, Christian Wurm, Rohit Karnaty, Haoran Li, Elaheh Ahmadi, Stacia Keller, James F. Buckwalter, Umesh K. Mishra
Summary: This manuscript presents the record-breaking performance of N-polar GaN deep recess MISHEMTs devices under continuous wave conditions, as well as several advancements including high OIP3 and low noise figure achieved through the zero-crossing of g(m3) at the peak of OIP3, reduced bias sensitivity of distortion, and power consumption reduction through fabrication process.
2022 IEEE/MTT-S INTERNATIONAL MICROWAVE SYMPOSIUM (IMS 2022)
(2022)
Proceedings Paper
Engineering, Electrical & Electronic
A. Raj, A. Krishna, N. Hatui, B. Romanczyk, C. Wurm, M. Guidry, R. Hamwey, N. Pakala, S. Keller, U. K. Mishra
Summary: In this study, GaN/AlGaN superlattice based MESFinFET devices were reported with MOCVD regrown p(+) contacts around the fins, achieving a normally-off operation with an on-current of 65 mA/mm and a large I-on/I-off >10^7. This represents a significant advancement in the development of large band gap pFET devices for efficient high voltage CMOS platforms in power conversion applications.
2021 IEEE INTERNATIONAL ELECTRON DEVICES MEETING (IEDM)
(2021)
Article
Chemistry, Multidisciplinary
Subhadip Das, Suchitra Prasad, Biswanath Chakraborty, Bhakti Jariwala, Sai Shradha, D. V. S. Muthu, Arnab Bhattacharya, U. V. Waghmare, A. K. Sood
Summary: In this study, the impact of electron doping on the vibrational modes of a bilayer ReS2 channel in a field-effect transistor was analyzed using Raman spectroscopy. The results showed that the frequency and linewidth of in-plane vibrational modes were affected by doping, while the out-of-plane modes remained unaffected. Density functional theory calculations provided a quantitative understanding of the strong electron-phonon coupling in the in-plane modes, which was attributed to a structural phase transition in ReS2.
Article
Crystallography
Jianzheng Hu, Long Yan, Ning Zhou, Yao Chen, Xiaoni Yang, Lianqiao Yang, Shiping Guo
Summary: The effect and mechanism of carrier gas velocity, V/III ratio, and carrier gas velocity match on the growth rate of AlN were investigated in this study. The results showed that the growth rate of AlN initially increased with hydrogen flow rate, reached saturation, and then decreased monotonically. The turning point value depended on the equipment and process. By increasing the MO VM, the growth rate of AlN could be improved, but the uniformity deteriorated due to turbulence and loss of uniform boundary layer. High quality AlN films were successfully grown on nano-patterned sapphire substrates with improved crystalline quality and atomic smooth surfaces.
JOURNAL OF CRYSTAL GROWTH
(2024)
Article
Crystallography
Tingting Ma, Yang Li, Kangning Sun, Qinglin Cheng, Sen Li
Summary: This study investigates the melting process and nucleation behavior of sodium crystals using molecular dynamics simulation. The results show good agreement between simulated and experimental values for the melting temperature, density, and radial distribution function of sodium. The diffusion coefficient of liquid sodium increases linearly with temperature, and the homogeneous nucleation rate of melting in superheated sodium crystal exponentially increases with temperature. The findings provide theoretical support for applications involving heat and mass transfer in sodium-related systems.
JOURNAL OF CRYSTAL GROWTH
(2024)
Article
Crystallography
Hisato Nishii, Shintarou Iida, Akira Yamasaki, Takumi Ikenoue, Masao Miyake, Toshiya Doi, Tetsuji Hirato
Summary: Epitaxial V2O3 films were fabricated on sapphire substrates using mist chemical vapor deposition (mist CVD) method, eliminating the need for high vacuum conditions. The films can be grown on sapphire substrates even under atmospheric pressure, with the optimal growth temperature at 823 K. The films grown at 823 K exhibit a metal-insulator transition at approximately 155 K. The film on C-plane sapphire exhibits a lower transition temperature compared to those on R- and A-plane sapphire substrates.
JOURNAL OF CRYSTAL GROWTH
(2024)
Article
Crystallography
Jani Jesenovec, Kevin Zawilski, Peter Alison, Stephan J. Meschter, Sambit K. Saha, Andrew J. Sepelak, Peter G. Schunemann
Summary: In this study, NiSb needles were successfully formed in InSb by manipulating the growth rate and adding NiSb. These needle structures in InSb can be used to tune the magnetoresistance of devices. Additionally, undoped InSb crystals demonstrated good infrared transmission at low growth rates.
JOURNAL OF CRYSTAL GROWTH
(2024)
Article
Crystallography
D. Joseph Daniel, P. Karuppasamy, H. J. Kim
Summary: The 2-amino 4-methyl pyridinium oxalate (2A4MPO) compound was synthesized and its crystal structure, functional groups, thermal stability, electrical properties, and third-order nonlinear optical properties were studied. The results demonstrate that the synthesized crystal has good structural integrity, thermal stability, and potential for third-order nonlinear optical applications.
JOURNAL OF CRYSTAL GROWTH
(2024)
Article
Crystallography
C. W. Lan
Summary: The past two decades have witnessed a significant transformation in solar silicon crystal growth, especially in the competition between multi-crystalline silicon (Multi-Si) and mono-crystalline silicon (Mono-Si). The demand for this crucial material has exponentially surged, with silicon solar panels capturing over 95% of the global PV market share. The advancements in crystal growth technology during this period have set historical benchmarks, with the market share shifting from high-performance multi-crystalline silicon (HPM-Si) to CZ silicon.
JOURNAL OF CRYSTAL GROWTH
(2024)
Article
Crystallography
Peiyao Hao, Lili Zheng, Hui Zhang
Summary: A novel design of argon gas tube for removing impurities during silicon ingot growth was developed, and numerical simulations showed that it can effectively extract SiO.
JOURNAL OF CRYSTAL GROWTH
(2024)
Article
Crystallography
Geetika Sahu, Chanchal Chakraborty, Subhadeep Roy, Souri Banerjee
Summary: This article discusses the novel fractal nature of hydrothermally synthesized MoS2 QDs. By adjusting the reaction time, the study found that the average size of QDs increases and then decreases with longer reaction times. STEM images indicate that shorter reaction times lead to sheet formation, while extended reaction times cause sheets to fragment into QDs.
JOURNAL OF CRYSTAL GROWTH
(2024)
Article
Crystallography
Pengjian Lu, Wei Huang, Junjun Wang, Haitao Yang, Shiyue Guo, Bin Li, Ting Wang, Chitengfei Zhang, Rong Tu, Song Zhang
Summary: A systematic study on the tetramethylsilane-hydorgen (TMS-H-2) system for the deposition of pure single-crystal SiC by high-temperature chemical vapor deposition (HTCVD) method is conducted. The study investigates the effect of temperature, pressure, and H-2:TMS ratio on the deposition conditions and provides a theoretical basis and guidance for improving the quality and cost of industrial production of single-crystal SiC.
JOURNAL OF CRYSTAL GROWTH
(2024)
Article
Crystallography
Xinyu Jiang, Liangliang Liu, Yanqing Liu, Yan Wang, Zhaoping Hou
Summary: Investigation on the preparation of anisometric templated textured high entropy or multi-element doped ferroelectric ceramics was conducted using A-site disordered niobate microcrystals. The effects of process parameters on the morphology and chemical composition were studied, and the photocatalytic properties of the microcrystals were evaluated.
JOURNAL OF CRYSTAL GROWTH
(2024)
Article
Crystallography
Mobashsara Tabassum, Md. Ashraful Alam, Sabrina Mostofa, Raton Kumar Bishwas, Debasish Sarkar, Shirin Akter Jahan
Summary: In this study, high crystallinity copper nanoparticles were synthesized by altering the reaction medium at low temperatures. The results show that changing the reaction medium can reduce the surface energy of precursors and promote the formation of highly crystalline copper nanoparticles.
JOURNAL OF CRYSTAL GROWTH
(2024)
Article
Crystallography
Ivan Bodnar, Vitaly V. Khoroshko, Veronika A. Yashchuk, Valery F. Gremenok, Mohsin Kazi, Mayeen U. Khandaker, Tatiana I. Zubar, Daria I. Tishkevich, Alex Trukhanov, Sergei Trukhanov
Summary: This work presents the production of single crystals of Cu2ZnGeSe4, a semiconducting quaternary compound, using a gas chemical method with iodine as a transporter. The phase state, crystal structure, and lattice constants of the synthesized samples were refined and determined. The band gap of Cu2ZnGeSe4 was calculated using transmission spectrum and it was found that the band gap increases by 12% with decreasing temperature in the range of 20-300 K.
JOURNAL OF CRYSTAL GROWTH
(2024)
Article
Crystallography
Timur Malin, Igor Osinnykh, Vladimir Mansurov, Dmitriy Protasov, Sergey Ponomarev, Denis Milakhin, Konstantin Zhuravlev
Summary: The effect of growth temperature on the buffer leakage currents of GaN-on-Si layers was investigated. It was found that higher growth temperature results in lower leakage currents. The defects in GaN layers grown at different temperatures were studied using photoluminescence technique, and a correlation between leakage currents, structural perfection, and donor concentration in GaN-on-Si layers was established. It was also observed that reduced growth temperature leads to the formation of inversion domains.
JOURNAL OF CRYSTAL GROWTH
(2024)
Article
Crystallography
Thi-Hoai-Thu Nguyen, Jyh-Chen Chen
Summary: The effect of heater power control on heat, flow, and oxygen transport for CCz crystal growth was studied. Shorter upper side heater design could improve crystal quality and growth, but with higher power consumption.
JOURNAL OF CRYSTAL GROWTH
(2024)
Article
Crystallography
Peter Rudolph
Summary: This article presents an overview of selected contributions to the development of crystal growth technology by the Laudise Prize awardee 2023. It discusses various aspects such as shaped crystal growth, the correlation between melt structure and crystal quality, control of intrinsic defects and inclusions, prevention of dislocation cell patterns, and melt growth experiments under a travelling magnetic field.
JOURNAL OF CRYSTAL GROWTH
(2024)
