Article
Chemistry, Physical
Marcela Socol, Nicoleta Preda, Carmen Breazu, Andreea Costas, Oana Rasoga, Gabriela Petre, Gianina Popescu-Pelin, Sorina Iftimie, Andrei Stochioiu, Gabriel Socol, Anca Stanculescu
Summary: Nanocomposite films based on macrocyclic compounds (ZnPc and TPyP) and metal oxide nanoparticles (ZnO or CuO) were prepared by MAPLE, and the effect of metal oxide addition on the properties of the films was evaluated. The presence of metal oxide nanoparticles influenced the infrared and UV-Vis spectra, as well as the photoluminescence spectra of the films. The morphology of the composite films showed agglomerated particles, but did not significantly affect the roughness. The electrical parameters of the structures based on the nanocomposite films were improved only for films with a certain type and optimum amount of metal oxide nanoparticles.
Article
Materials Science, Coatings & Films
Rommel Paulo B. Viloan, Ulf Helmersson, Daniel Lundin
Summary: The growth of Cu thin films by low-energy ion-bombardment using bipolar and conventional HiPIMS pulse configurations was studied with different biasing methods of the substrate. The substrate biasing method can affect ion current distribution and crystal growth trends.
SURFACE & COATINGS TECHNOLOGY
(2021)
Review
Materials Science, Multidisciplinary
Marcela Socol, Nicoleta Preda, Gabriel Socol
Summary: Solar power is a sustainable solution that can provide cheap and clean energy, contributing positively to climate change. Organic photovoltaic cells have shown great potential, but challenges lie in selecting the right organic compounds and manufacturing techniques to improve their performance. Advanced laser deposition techniques, such as MAPLE, offer promising developments for enhancing the efficiency of OPV cells in the future.
Article
Materials Science, Multidisciplinary
Lei Zhang, Feng Xu, Jian Zhang, Baoru Bian, Yong Hu, Fei Xue, Juan Du
Summary: This study presents a new method for fabricating large-scale Fe3O4 nanoparticle monolayer films and demonstrates the significant role of inter-particle interactions in the formation of magnetic anisotropy.
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
(2022)
Article
Physics, Applied
Grzegorz Sadowski, Yongbin Zhu, Rui Shu, Tao Feng, Arnaud le Febvrier, Denis Music, Weishu Liu, Per Eklund
Summary: In this study, Mg3Bi2 films with good thermoelectric properties were successfully synthesized at low temperatures, and the epitaxial growth relationship between Mg3Bi2 and the substrate was observed.
APPLIED PHYSICS LETTERS
(2022)
Article
Energy & Fuels
Daniela De Luca, V. Amrutha, V. Praveen Kumar, S. Latha, Parthasarathi Bera, Antonio Caldarelli, Eliana Gaudino, Roberto Russo, Harish C. Barshilia
Summary: Thin films of hafnium and hafnium carbide were deposited using pulsed magnetron sputtering in an atmosphere of argon and acetylene. Different flow rates of acetylene gas were used to form distinct HfCx compounds and analyze their properties. The accurate knowledge of the complex refractive index of HfCx is essential for designing optical structures for energy conversion purposes.
SOLAR ENERGY MATERIALS AND SOLAR CELLS
(2023)
Article
Chemistry, Multidisciplinary
Zhong Tian, Han Yan, Qing Peng, Lin Jay Guo, Shengjun Zhou, Can Ding, Peng Li, Qi Luo
Summary: This study investigated the effect of aluminum doping on the surface morphology of ultra-thin silver films, revealing that Al-doped silver films exhibited smaller surface roughness at various substrate temperatures. The addition of aluminum dopants promoted the immobilization of silver atoms on SiO2 substrate, resulting in a smoother surface attributed to the reduced mean free path of silver due to the cage effect by the aluminum dopant.
Article
Physics, Condensed Matter
Nazakat Ali, S. Hussain, M. Waqas, M. Faheem, N. Ahmad, A. Ali, M. Yasir Ali, K. Mahmood, Lukas Schmidt-Mende
Summary: The deposition potential has an impact on the properties of cuprous oxide (Cu2O) thin films formed on copper (Cu) substrates. XRD analysis shows that the films have a cubic structure with desired (111) growth orientation. SEM observations reveal that the Cu2O film consists of well-distributed three-sided pyramid-shaped grains on the Cu substrate, which change significantly with the plating potential. The photo-current density of the prepared Cu2O thin films increases with the deposition potential and the films produced at -0.6 V have the highest electron transfer efficiency.
PHYSICA B-CONDENSED MATTER
(2023)
Article
Nanoscience & Nanotechnology
S. Levcenko, B. Teymur, D. B. Mitzi, T. Unold
Summary: Characterization of radiative transitions in trigonal Cu2BaSnS4 was experimentally studied via temperature and excitation intensity dependent photoluminescence measurements, revealing the contributions of free exciton, bound exciton, donor-acceptor-pair recombination, and free-to-bound transition. The activation energies and temperature shift for the radiative transitions were determined, with optical phonons playing a significant role in the energy shift of free exciton recombination above 90 K.
Article
Chemistry, Physical
K. Manjunath, A. Saraswat, D. Samrat, C. N. R. Rao
Summary: Ti2O3 thin films were prepared by atomic layer deposition and their electrical resistivity was measured as a function of temperature. The films remained stable for up to three weeks and showed an insulator-metal transition at around 80 K, with a significant change in resistivity. The anomalous increase in resistivity in the films is consistent with the two-band model and is dependent on the crystallographic c/a ratio.
Article
Anatomy & Morphology
Amir Zelati, Mohsen Mardani, Sahar Rezaee, Robert S. Matos, Marcelo A. Pires, Henrique D. da Fonseca Filho, Abhijeet Das, Fatemeh Hafezi, Ghasem Amraee Rad, Sanjeev Kumar, Stefan Talu
Summary: In this study, the morphological properties and micro-roughness of chromium thin films were analyzed using atomic force microscope (AFM) on different substrates of BK7, Silicon (Si), and glass, prepared by thermal evaporation technique and confirmed via EDS analysis. The analysis showed differences in the growth of chromium thin films between glass substrate and the other two substrates (BK7 and Si). Multifractality of the Cr thin films deposited on all studied substrates was observed, with glass substrates displaying the strongest multifractality indicating the distribution of space filling properties over more spatial scales compared to BK7 and Si samples.
MICROSCOPY RESEARCH AND TECHNIQUE
(2023)
Review
Chemistry, Multidisciplinary
Marcela Socol, Nicoleta Preda
Summary: The continuous growth in global energy consumption, combined with increasing concerns about climate change and environmental pollution, are driving forces behind the deployment of renewable energy sources. Solar energy, being the most abundant and cleanest form of renewable energy, is seen as a viable pathway for sustainable energy generation. Hybrid solar cells, utilizing nanocomposite layers, have received significant research attention due to their ability to combine the benefits of both organic and inorganic components.
Article
Chemistry, Physical
Laura M. Jacoby, Matthew J. Crane, Daniel R. Gamelin
Summary: This research discovers the potential application of vapor-deposited CsPbBr3 thin films in optoelectronic and spin-based devices. Both photogenerated holes and electrons show coherent spin precession, but the spin dephasing time of photogenerated electrons is shorter.
CHEMISTRY OF MATERIALS
(2022)
Article
Biochemistry & Molecular Biology
Agata Niemczyk, Simona Brajnicov, Veronica Satulu, Jolanta Baranowska, Bogdana Mitu, Maria Dinescu
Summary: Through the MAPLE technique, coatings with various morphologies and topographies can be obtained by changing the process parameters. Chemical structure analysis reveals that the ester group in EVA coatings transforms into ketone and carboxyl groups, with some changes in the aliphatic main chain.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2021)
Article
Materials Science, Multidisciplinary
Tuo Sheng, Xing-Zhao Liu, Ling-Xuan Qian, Bo Xu, Yi-Yu Zhang
Summary: Metal-semiconductor-metal solar-blind ultraviolet photoconductors based on beta-Ga2O3 thin films were fabricated and the effects of annealing on their characteristics and photoconductivity were studied. Higher annealing temperature resulted in lower crystalline quality and device photoresponsivity. The vacuum-annealed sample showed the highest photoresponsivity and the oxygen-annealed sample effectively suppressed persistent photoconductivity.
Article
Nanoscience & Nanotechnology
Alireza Assar, Filipe Martinho, Jes Larsen, Nishant Saini, Denver Shearer, Marcos V. Moro, Fredrik Stulen, Sigbjorn Grini, Sara Engberg, Eugen Stamate, Jorgen Schou, Lasse Vines, Stela Canulescu, Charlotte Platzer-Bjorkman, Ole Hansen
Summary: Multijunction solar cells in a tandem configuration using crystalline silicon as the bottom cell can reduce electricity costs. However, only a limited number of top and bottom cell architectures are compatible for direct integration on silicon. By using polySi/SiOx passivating contacts, degradation can be minimized and the lifetime of the bottom cell can be increased. Applying this concept to low-cost top cell chalcogenides, the efficiency and resilience of the tandem solar cells can be improved.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Materials Science, Multidisciplinary
Mungunshagai Gansukh, Alireza Assar, Filipe Martinho, Simon Lopez Marino, Moises Espindola-Rodriguez, Sara Engberg, Eugen Stamate, Jorgen Schou, Ole Hansen, Stela Canulescu
Summary: In this study, a barrier layer consisting of an ultrathin layer of Al between two TiN films is introduced to prevent Cu diffusion into Si in CZTS-Si tandem solar cells. The nature of the precursors is found to affect the chemical composition of the barrier layer, and CZTS/Si tandem solar cells based on oxide precursors demonstrate superior performance compared to those based on sulfide precursors.
APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
(2022)
Article
Materials Science, Ceramics
Sara Engberg, Mungunshagai Gansukh, Filipe Martinho, Eugen Stamate, Ole Hansen, Jorgen Schou, Stela Canulescu
Summary: This study successfully incorporated silver into the CZTS lattice using cation substitution, which reduced the disorder and band tailing effects. The best efficiency was achieved with 13% Ag/(Ag+Cu), reaching 4.9%. In addition, silver incorporation also improved grain growth and increased the band gap.
CERAMICS INTERNATIONAL
(2022)
Article
Medicine, General & Internal
Eduard Gheorghe Gatin, Pal Nagy, Stefan-Marian Iordache, Ana-Maria Iordache, Catalin Romeo Luculescu
Summary: The aim of this study was to evaluate the quality of bone using in vivo Raman spectroscopy and to identify different phases of calcified tissues in relation to periodontitis. The researchers performed Raman spectroscopy measurements in vivo during surgery and ex vivo on harvested bone samples from ten patients. The intensity variation of the Raman spectrum reflected the bone quality and was strongly linked to the patients' medical status. Additionally, the fluorescence of the bone samples was related to collagen content, allowing for a comprehensive assessment of bone quality and healing process.
Article
Materials Science, Multidisciplinary
Alexandra Tsekou, Filipe Martinho, Denys Miakota, Stela Canulescu, Sara Engberg
Summary: This study investigates the effect of soft-annealing on the efficiency of CZTS kesterite solar cells. The results show that the highest device efficiency of 6.1% is achieved at a soft-annealing temperature of 150 degrees C. Further increase in the soft-annealing temperature leads to a decrease in device efficiency. Raman spectroscopy analysis reveals that soft-annealing affects the Cu/Zn disorder in the CZTS absorbers, with a higher ordering observed at 150 degrees C, which correlates with the highest device efficiency. Additionally, the composition and morphology of the absorbers are minimally affected by the soft-annealing process.
APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
(2022)
Article
Materials Science, Multidisciplinary
Joan Ramish Esterlich, Kevin Affannoukoue, Reelika Kaupmees, Denys Miakota, Sara Engberg, Maarja Grossberg-Kuusk, Jorgen Schou, Stela Canulescu
Summary: This paper presents advances in synthesizing sulfide thin films using a hybrid approach of pulsed laser deposition (PLD) combined with a sulfur cracker beam. The study demonstrates a facile and non-toxic method for fabricating 2D materials of MoS2 and sulfide kesterites of CZTS, overcoming drawbacks related to toxic reactants and non-vacuum conditions. The research also shows the high-temperature synthesis of mono- and multilayers of MoS2 and the one-step synthesis of CZTS using PLD with the deposition of reactive sulfur molecules.
APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
(2023)
Article
Chemistry, Physical
Nicoleta Enea, Valentin Ion, Cristian Viespe, Izabela Constantinoiu, Octavian Buiu, Cosmin Romanitan, Nicu Doinel Scarisoreanu
Summary: In this study, the specific interaction between a modified surface and various gases in gas sensor applications was investigated. The sensitivity of the sensor was enhanced by depositing a conductive polymer on the surface of a piezoelectric ceramic material. The frequency responses of the sensors to different gases were measured to observe differences in their performance based on deposition conditions.
Article
Chemistry, Physical
Choongman Moon, Filipe Mesquita Alves Martinho, Gihun Jung, Jaehyuk Koh, Alireza Assar, Sung-Wook Nam, Stela Canulescu, Byungha Shin
Summary: A tandem photoelectrochemical (PEC) water-splitting device consisting of two light absorbers with different bandgaps is developed. Silicon photoelectrodes with a bandgap of 1.12 eV are used as the low bandgap bottom cells of the tandem device. By applying a tunnel oxide passivated contact (TOPCon) on the front and back sides of a Si wafer, TOPCon Si photoelectrodes exhibit superior photovoltage and thermal stability. Two wired tandem PEC devices based on earth-abundant materials, a BiVO4 photoanode-TOPCon Si photocathode and a halide perovskite photocathode-TOPCon Si photoanode, are tested and show STH conversion efficiencies of 0.24% and 3.6%, respectively.
JOURNAL OF MATERIALS CHEMISTRY A
(2023)
Article
Chemistry, Multidisciplinary
Rajesh Kumar Ulaganathan, Pradip Kumar Roy, Swapnil Milind Mhatre, Raghavan Chinnambedu Murugesan, Wei-Liang Chen, Man-Hong Lai, Ambika Subramanian, Chang-Yu Lin, Yu-Ming Chang, Stela Canulescu, Alex Rozhin, Chi-Te Liang, Raman Sankar
Summary: A stable centimeter-long 2D hybrid perovskite single crystal, (N-MPDA)[PbBr4], using divalent N1-methylpropane-1,3-diammonium cation as an organic spacer, is reported. The single crystal exhibits stable optoelectronic performance, low threshold random lasing, and multi-photon luminescence/multi-harmonic generation. It also shows excellent photoresponsivity and large specific detectivity in a photoconductive device.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Ganesh Ghimire, Rajesh Kumar Ulaganathan, Agnes Tempez, Oleksii Ilchenko, Raymond R. Unocic, Julian Heske, Denys I. Miakota, Cheng Xiang, Marc Chaigneau, Tim Booth, Peter Boggild, Kristian S. Thygesen, David B. Geohegan, Stela Canulescu
Summary: MoS2 nanoribbons and triangular crystals can be grown by reacting MoOx films with NaF in a sulfur-rich environment. The nanoribbons show single-layer edges and exhibit second harmonic generation, while the multilayer structure does not. Raman spectra of the nanoribbons show distinct contributions from the single-layer edges and multilayer core. An ultrasensitive photodetector made of a single MoS2 nanoribbon with high responsivity is also reported. These findings have implications for the design of efficient optoelectronic devices using MoS2 semiconductors.
ADVANCED MATERIALS
(2023)
Article
Chemistry, Physical
Denys I. Miakota, Ganesh Ghimire, Rajesh Kumar Ulaganathan, Moises E. Rodriguez, Stela Canulescu
Summary: Alkali-assisted chemical vapor deposition has been proven effective in growing large single crystals of transition metal dichalcogenides. In this study, a vapor-liquid-solid phase reaction between MoOx precursors and metal alkali halide (i.e., NaF) was utilized to synthesize highly crystalline MoS2 nanoribbons. The growth process involves the formation of Na-Mo-O liquid phase in a sulfur-rich environment. The as-grown MoS2 nanoribbons are surrounded by mono- and multilayer triangles of MoS2 and exhibit a preferential alignment dictated by both crystal symmetry and substrate. The method offers flexibility in designing nanoelectronic devices based on tunable TMD dimensions.
APPLIED SURFACE SCIENCE
(2023)
Article
Materials Science, Ceramics
Ana Violeta Filip, Alexandra Maria Isabel Trefilov, Lucica Boroica, Marius Catalin Dinca, Mihail Elisa, Ileana Cristina Vasiliu, Nicolae Tigau, Simona Brajnicov, Marius Dumitru, Catalin Luculescu, Oana Gherasim Fufa, Bogdan Alexandru Sava
Summary: Boro-phosphate glass-graphene oxide nanocomposites combine nanocarbon electrical properties with the optical and host properties of glass, making them potential candidates for optoelectronic, photonic materials, and bio-applications.
JOURNAL OF NON-CRYSTALLINE SOLIDS
(2023)
Article
Chemistry, Physical
Gihun Jung, Choongman Moon, Filipe Martinho, Yonghoon Jung, Jinwoo Chu, Hyewon Park, Alireza Hajijafarassar, Rasmus Nielsen, Jorgen Schou, Jeongyoung Park, Peter Christian Kjaergaard Vesborg, Ole Hansen, Yunseog Lee, Stela Canulescu, Byungha Shin
Summary: A photoelectrochemical water splitting device based on a dual-junction monolithic tandem cell with high performance was developed. The device achieved the highest photocurrent density and solar-to-hydrogen conversion efficiency among dual-junction monolithic photoelectrochemical cells, except for III-V materials. The use of TOPCon Si, TTO and SnO2 in the device contributed to its stability and high efficiency.
ADVANCED ENERGY MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Moritz Fischer, Ali Sajid, Jake Iles-Smith, Alexander Hoetger, Denys I. Miakota, Mark K. Svendsen, Christoph Kastl, Stela Canulescu, Sanshui Xiao, Martijn Wubs, Kristian S. Thygesen, Alexander W. Holleitner, Nicolas Stenger
Summary: By combining theory and experiments, we have identified three carbon-based defects as the microscopic origin of luminescent centers in hBN. We have also developed a method to calculate photoluminescence excitation (PLE) maps, which accurately describe the vibronic structure of the optical transition and the phonon-assisted excitation mechanism.
Article
Chemistry, Physical
Francesco Cordero, Floriana Craciun, Patrizia Imperatori, Venanzio Raglione, Gloria Zanotti, Antoniu Moldovan, Maria Dinescu
Summary: In this study, we measured the properties of a metal-free molecular perovskite material and found that it exhibits ferroelectricity below a certain temperature. We also observed that the material deteriorates and loses mass at high temperatures, leading to a decrease in performance. Unlike traditional ferroelectric materials, the elastic modulus of this material weakens before the ferroelectric phase. The degradation of the material is attributed to point defects, and a method for calculating the defect concentration is proposed.
