Article
Materials Science, Multidisciplinary
Philipp Storm, Susanne Selle, Holger von Wenckstern, Marius Grundmann, Michael Lorenz
Summary: Transparent, p-type semiconductor copper iodide (CuI) thin films were grown via pulsed laser deposition on SrF2(111) using water soluble sacrificial layers of sodium bromide (NaBr). The resulting CuI thin films are single crystalline with reduced surface roughness compared to epitaxial CuI grown with rotational domains on other templates. The CuI thin films were subsequently transferred onto glass using epoxy/glue and dissolution of NaBr in a water-vapor atmosphere.
JOURNAL OF MATERIALS CHEMISTRY C
(2022)
Article
Materials Science, Multidisciplinary
Hyung-Jin Choi, Jinhyuk Jang, Soo Young Jung, Ruiguang Ning, Min-Seok Kim, Sung-Jin Jung, Jun Young Lee, Jin Soo Park, Byung Chul Lee, Ji-Soo Jang, Seong Keun Kim, Kyu Hyoung Lee, June Hyuk Lee, Sung Ok Won, Yulan Li, Shenyang Hu, Si-Young Choi, Seung-Hyub Baek
Summary: In this study, a simple annealing technique was reported to significantly improve the crystalline quality of YSZ on Si substrates by utilizing thermal stresses and the difference in thermal expansion coefficients. High-quality epitaxial CeO2 and Y:HfO2 thin films were successfully integrated on YSZ/Si substrates using this method.
JOURNAL OF MATERIALS CHEMISTRY C
(2022)
Article
Physics, Applied
Xuelin Yang, Jianfei Shen, Zidong Cai, Zhenghao Chen, Bo Shen
Summary: This study investigates the influence of C doping on dislocation behaviors in GaN. It is found that moderate C doping can reduce dislocation density, but further increasing C concentration leads to an increase in dislocation density. Additionally, C doping has a greater impact on edge dislocations than screw dislocations. The stress evolution in the GaN layer is consistent with the observed dislocation behaviors, suggesting a mechanism where C impurities are incorporated into different lattice locations in GaN with increasing doping levels.
APPLIED PHYSICS EXPRESS
(2022)
Article
Materials Science, Multidisciplinary
Khushboo Kumari, Sandeep Vura, Srinivasan Raghavan, Sushobhan Avasthi
Summary: The pulsed Nd:YAG laser was used to crystallize amorphous germanium thin-films, resulting in epitaxial Ge, with film thickness and laser fluence playing a crucial role. The epitaxial Ge preparation method is fast, cost-effective, and has a low thermal budget, making it suitable for large area applications.
Article
Chemistry, Multidisciplinary
Sebastiano Caccamo, Rosaria Anna Puglisi
Summary: This study presents a molecular doping method using phosphoric acid as a dopant precursor, which allows for higher predetermined surface density and electrical carrier doses compared to traditional methods using organic molecules as precursors.
Article
Nanoscience & Nanotechnology
Xiao Tang, Kuang-Hui Li, Yue Zhao, Yanxin Sui, Huili Liang, Zeng Liu, Che-Hao Liao, Wedyan Babatain, Rongyu Lin, Chuanju Wang, Yi Lu, Feras S. Alqatari, Zengxia Mei, Weihua Tang, Xiaohang Li
Summary: The study demonstrates the epitaxial growth of technically important beta-Ga2O3 semiconductor thin films on flexible CeO2(001)-buffered Hastelloy tape, leading to the fabrication of flexible photodetectors with excellent photoelectrical performance. The photodetectors exhibit a responsivity of 4 X 10(4) mA/W and remain robust after more than 20,000 bending test cycles, showing potential for future applications in flexible oxide semiconductor devices.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Materials Science, Multidisciplinary
Fang Li, Yani An, Tiefeng Yang, Changlin Yu
Summary: In this study, a bilayer MoS2/MoSe2 vdW heterostructure with an atomic-layer clean interface was successfully prepared using an iodine-assisted growth strategy, and it was shown to exhibit enhanced photoresponsivity. This study provides an important reference for the controlled growth of TMDs vdW heterostructures.
Article
Physics, Applied
Jarod E. Meyer, Leland Nordin, Tri Nguyen, Kunal Mukherjee
Summary: The study investigates the effects of rapid thermal annealing on the structure and photoluminescence of PbSe thin films grown on GaAs (001) at low temperatures. It is found that annealing leads to extensive re-crystallization and transformation of grain boundaries, resulting in improved photoluminescence properties. This research is important for the integration of PbSe infrared optoelectronics at low temperatures.
APPLIED PHYSICS LETTERS
(2023)
Article
Chemistry, Physical
Ye Yuan, Yufang Xie, Ning Yuan, Mao Wang, Rene Heller, Ulrich Kentsch, Tianrui Zhai, Xiaolei Wang
Summary: In this study, co-doping of (In,Mn)As diluted magnetic semiconductors by Al was conducted for the first time using co-implantation and pulsed laser annealing technique. The structural and magnetic properties were systematically investigated, showing a decrease in Curie temperature, magnetization, and uniaxial magnetic anisotropies with increased aluminum incorporation, possibly due to enhanced carrier localization or suppression of substitutional Mn atoms.
Article
Materials Science, Multidisciplinary
Junichi Murota, Hiromu Ishii
Summary: The in-situ doping process of B and P in CVD Si and Si1-xGex (100) epitaxial growth was investigated using SiH4-GeH4-dopant gas (B2H6 or PH3)-H2 gas mixture. The study proposed mechanisms for in situ doping at different dopant gas partial pressures and showed good agreement with experimental data.
ECS JOURNAL OF SOLID STATE SCIENCE AND TECHNOLOGY
(2021)
Article
Chemistry, Multidisciplinary
Nguyen Ngan Nguyen, Hyo Chan Lee, Kangkyun Baek, Min Seok Yoo, Hansol Lee, Hyungsub Lim, Shinyoung Choi, Cheol-Joo Kim, SungWoo Nam, Kilwon Cho
Summary: The hybrid graphene template enables the preparation of highly crystalline organic semiconductor thin films with large grain sizes. Compared to conventional graphene templates, phototransistors fabricated on this hybrid template exhibit significantly higher photoresponsivity.
ADVANCED FUNCTIONAL MATERIALS
(2021)
Article
Nanoscience & Nanotechnology
Jinghai Li, Adara Babuji, Lamiaa Fijahi, Ann Maria James, Roland Resel, Tommaso Salzillo, Raphael Pfattner, Carmen Ocal, Esther Barrena, Marta Mas-Torrent
Summary: In this study, it was found that contact resistance and charge trapping are two key obstacles that negatively affect the performance of organic field-effect transistors (OFETs). By using CH3CN vapor annealing and doping procedures, the interfacial shallow traps and deeper traps in the organic semiconductor (OSC) film can be effectively reduced, resulting in a significant reduction of contact resistance. Moreover, the devices treated with I2/CH3CN demonstrate ideal electrical characteristics with negligible levels of shallow/deep traps and highly gate-independent mobility. Therefore, this work highlights the promising synergistic effects of simultaneous solvent vapor annealing and doping, which can effectively eliminate contact resistance problems in OSC films.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Engineering, Electrical & Electronic
Kazuki Shimazoe, Hiroyuki Nishinaka, Keisuke Watanabe, Masahiro Yoshimoto
Summary: In this study, rh-ITO thin films with different Sn concentrations were successfully grown using the mist chemical vapor deposition method. The films exhibited low resistivity, high transmittance, and can be used as transparent conductive oxide materials.
MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING
(2022)
Article
Chemistry, Multidisciplinary
Zakhar R. Kudrynskyi, Illya Mintyanskii, Petro Savitskii, Zakhar D. Kovalyuk
Summary: This study provides important knowledge of the effect of cobalt impurities on the physical properties of InSe, which is crucial for tailoring the parameters of this semiconductor for applications in electronics and spintronics.
APPLIED SCIENCES-BASEL
(2022)
Article
Chemistry, Inorganic & Nuclear
Wenyuan Tan, Xiaoqian Tang, Lin Dou, Huan Zhang
Summary: To improve the photocatalytic performance of Bi2WO6, La-doped Bi2WO6 photocatalysts were prepared and characterized. The results showed that La doping increased the level of oxygen vacancies in Bi2WO6 and enhanced the separation of photoinduced carriers and the generation of superoxide radicals. Under simulated sunlight irradiation, La-Bi2WO6 exhibited higher photocatalytic activity compared to pure Bi2WO6.
INORGANIC CHEMISTRY COMMUNICATIONS
(2022)
Article
Chemistry, Multidisciplinary
Zahra Barani, Tekwam Geremew, Megan Stokey, Nicholas Sesing, Maedeh Taheri, Matthew J. Hilfiker, Fariborz Kargar, Mathias Schubert, Tina T. Salguero, Alexander A. Balandin
Summary: This study demonstrates a unique class of quantum composites based on polymers with fillers composed of a van der Waals quantum material. These composites reveal multiple charge-density-wave quantum condensate phases. Typically, materials exhibiting quantum phenomena are crystalline, pure, and have few defects. However, in this research, the macroscopic charge-density-wave phases of the filler particles are successfully preserved even after multiple composite processing steps. The prepared composites display strong charge-density-wave phenomena at temperatures even above room temperature and show potential for advanced applications in energy storage and electronics.
ADVANCED MATERIALS
(2023)
Article
Physics, Applied
Dat Q. Tran, Ferenc Tasnadi, Agne Zukauskaite, Jens Birch, Vanya Darakchieva, Plamen P. Paskov
Summary: Due to their large piezoelectric coefficients and spontaneous polarizations, (Sc,Y) xAl(1-x)N alloys are a promising class of III-nitride semiconductor materials for high-frequency electronic and acoustic devices. This study measures the thermal conductivity of ScxAl1-xN and YxAl1-xN (0 ≤ x ≤ 0.22) layers using the transient thermoreflectance technique. The results show that the thermal conductivity of both alloys decreases with increasing Sc(Y) composition compared to AlN, and YxAl1-xN has a lower thermal conductivity than ScxAl1-xN for all compositions. The contributions of different phonon-scattering mechanisms to the thermal conductivity of (Sc,Y) xAl(1-x)N alloys are analyzed and discussed.
APPLIED PHYSICS LETTERS
(2023)
Article
Physics, Applied
A. Papamichail, A. R. Persson, S. Richter, P. Kuhne, V. Stanishev, P. O. A. Persson, R. Ferrand-Drake Del Castillo, M. Thorsell, H. Hjelmgren, P. P. Paskov, N. Rorsman, V. Darakchieva
Summary: Compositionally graded channel AlGaN/GaN high electron mobility transistors (HEMTs) with different grading profiles of a 10-nm-thick AlxGa1-xN channel are demonstrated using hot-wall metal-organic chemical vapour deposition (MOCVD). The growth process is optimized by correlating the Al-profiles and the interface sharpness with specific MOCVD process parameters. The impact of incorporating a thin AlN interlayer on the HEMT properties is investigated. The results show improved device linearity for the optimized graded channel HEMT structure.
APPLIED PHYSICS LETTERS
(2023)
Article
Engineering, Environmental
Kazi Albab Hussain, Svetlana Romanova, Ilhami Okur, Dong Zhang, Jesse Kuebler, Xi Huang, Bing Wang, Lucia Fernandez-Ballester, Yongfeng Lu, Mathias Schubert, Yusong Li
Summary: This study revealed that microwave heating caused the highest release of microplastics and nanoplastics into food compared to other usage scenarios. Plastic containers and reusable food pouches can release millions to billions of particles through refrigeration, room-temperature storage, and microwave heating. The released microplastics and nanoplastics can potentially lead to cell death and pose risks to infants and toddlers.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2023)
Article
Physics, Applied
S. Magalhaes, J. S. Cabaco, O. Concepcion, D. Buca, M. Stachowicz, F. Oliveira, M. F. Cerqueira, K. Lorenz, E. Alves
Summary: The study demonstrates the importance of accurately determining the strain states of semiconductor compounds and introduces a new software called LAPAs. The lattice parameters and chemical composition of Al1-xInxN and Ge1-xSnx compounds grown on different substrates are calculated using the Bond's method and compared with results from x-ray diffraction. The findings show that broad peaks contribute significantly to the uncertainty in lattice parameters, and the inclusion of refraction correction has a small impact on the results. The differences between real space and reciprocal space methods are also discussed.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2023)
Article
Instruments & Instrumentation
Przemyslaw Jozwik, Afonso Cacador, Katharina Lorenz, Renata Ratajczak, Cyprian Mieszczynsk
Summary: There is a long-standing interest in studying radiation damage caused by ion beams, which are present in space or the nuclear industry and used in materials modification. Rutherford Backscattering Spectrometry in channeling mode (RBS/C) is commonly employed to analyze the damage, but the presence of various defect types makes interpretation of RBS/C spectra challenging. To address this issue, the McChasy Monte Carlo simulation code was developed, which utilizes small simulation cells to analyze channeling data in crystals with different defect types. This study introduces a new feature of the code, a model of dislocation loops, and validates its effectiveness by analyzing RBS/C experiments performed at different beam energies for Eu-implanted GaN with an energy of 300 keV.
NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS
(2023)
Article
Physics, Multidisciplinary
C. M. Vitor, E. Alves, R. C. da Silva, R. Mateus, J. Cruz, N. Catarino
Summary: In this study, ion beam analysis techniques were used to investigate the Be-related plasma-wall interactions. New data sets for the differential cross sections Be-9(He-3,p( i ))B-11 were obtained, and the results were found to be consistent with previous studies. A benchmarking measurement was performed to validate the results.
Article
Multidisciplinary Sciences
D. M. Esteves, A. L. Rodrigues, L. C. Alves, E. Alves, M. I. Dias, Z. Jia, W. Mu, K. Lorenz, M. Peres
Summary: Ion-beam-induced luminescence (IBIL) measurements were performed in Cr-doped β-Ga2O3, showing a strong enhancement of the Cr3+ luminescence upon ion irradiation. The effective cross-sections associated with the defect-induced IBIL enhancement and quenching processes were estimated through theoretical modelling. Thermoluminescence (TL) studies revealed that the TL emission corresponding to the Cr3+ luminescence can be activated by ion irradiation and quenched by annealing, suggesting the role of irradiation-induced defects.
SCIENTIFIC REPORTS
(2023)
Article
Nuclear Science & Technology
Y. Zayachuk, N. Catarino, C. Smith, I. Jepu, C. Ayres, A. Widdowson, E. Alves, M. Rubel, JET Contributors
Summary: In this study, beryllium samples with co-deposits or surface cracks caused by melt damage were immersed into boiling water to simulate the impact of coolant water ingress into a tokamak. The results showed that there was no thermomechanical damage to the samples during exposure, and no measurable release of deuterium occurred. Only some degree of surface oxidation was observed, but no thick oxide films were formed.
NUCLEAR MATERIALS AND ENERGY
(2023)
Article
Physics, Applied
Axel R. R. Persson, Anders Gustafsson, Zhaoxia Bi, Lars Samuelson, Vanya Darakchieva, Per O. A. Persson
Summary: In this study, we investigated the optical properties of InGaN platelets with a quantum well structure for nano-LEDs emitting red light and their correlation with the atomic structure. Using cathodoluminescence measurements and a spectroscopy-thinning-imaging method, we observed how stacking mismatch boundaries intersect with the quantum well in plan-view and result in diminished cathodoluminescence intensity. The findings emphasize the significance of avoiding stacking mismatch in small LED structures due to the presence of relatively large non-radiative recombination regions caused by the mismatch boundaries.
APPLIED PHYSICS LETTERS
(2023)
Article
Engineering, Electrical & Electronic
Philipp Gribisch, Rosalia Delgado Carrascon, Vanya Darakchieva, Erik Lind
Summary: In this study, fully-vertical GaN FinFETs with a gate length of 550 nm were fabricated and analyzed. The devices exhibited normally-OFF behavior, with subthreshold swings close to the limit of 60 mV/dec. Low hysteresis values indicated low defect densities at the oxide/GaN interface. The devices also showed low specific ON-resistances at a maximum breakdown voltage of around 90 V, which is reasonable for the given drift layer thickness of 1 μm. Capacitance voltage measurements were used to model and identify the capacitances in the devices, and the effective and field effect mobility in the channel were approximated to be around 164 and 54 cm²/(Vs) at higher gate voltages, representing a slight improvement compared to reported values for similar devices.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2023)
Article
Engineering, Electrical & Electronic
A. Cacador, P. Jozwik, S. Magalhaes, J. G. Marques, E. Wendler, K. Lorenz
Summary: Ion implantation provides precise control over various parameters in material doping, but it also causes ion-induced damage. This study used Rutherford Backscattering Spectrometry in Channeling mode to analyze the defect profiles in GaN samples implanted with different fluences of Europium ions. The results showed that the damage increased with fluence in a complex manner, indicating the presence of multiple defect types and elaborate defect evolution mechanisms.
MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING
(2023)
Article
Instruments & Instrumentation
Cyprian Mieszczynski, Przemyslaw Jozwik, Kazimierz Skrobas, Kamila Stefanska-Skrobas, Renata Ratajczak, Jacek Jagielski, Frederico Garrido, Edyta Wyszkowska, Alexander Azarov, Katharina Lorenz, Eduardo Alves
Summary: In this work, the unique capability of the new version of the McChasy code (called McChasy2) to simulate experimental energy spectra delivered by Rutherford Backscattering Spectrometry in channeling direction (RBS/C) using large atomic structures (ca. 108 atoms) is presented. The focus is on the simulations of extended structural defects (edge dislocations and loops) formed inside nickel-based single-crystal alloys, which are widely studied and promising materials for high-temperature applications.
NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS
(2023)
Article
Chemistry, Multidisciplinary
Chaoyang Kuang, Shangzhi Chen, Min Luo, Qilun Zhang, Xiao Sun, Shaobo Han, Qingqing Wang, Vallery Stanishev, Vanya Darakchieva, Reverant Crispin, Mats Fahlman, Dan Zhao, Qiye Wen, Magnus P. Jonsson
Summary: This study demonstrates that conducting polymer-cellulose aerogels can provide large modulation range for broadband THz light and maintain low reflection loss. These low-cost, aqueous solution-processable, sustainable, and bio-friendly aerogels may play an important role in next-generation intelligent THz devices.
Article
Nanoscience & Nanotechnology
Arnar M. Vidarsson, Axel R. Persson, Jr-Tai Chen, Daniel Haasmann, Jawad Ul Hassan, Sima Dimitrijev, Niklas Rorsman, Vanya Darakchieva, Einar O. Sveinbjornsson
Summary: Recent research suggests that very fast interface traps are the main cause of poor channel-carrier mobility in SiC metal-oxide-semiconductor field effect transistors. NI traps are defects located inside the SiO2 dielectric and are closely related to the SiC surface region.
