Article
Materials Science, Multidisciplinary
Aleksandr Lenshin, Pavel Seredin, Dmitry Goloshchapov, Ali O. Radam, Andrey Mizerov
Summary: For the first time, this study demonstrates the advantages of using a compliant hybrid substrate of porSi/SiC for growing high-quality ultra-thin nanostructured AlxGa1-xN/GaN heterostructures using molecular beam epitaxy. The experimental and computational data obtained in this work are important for understanding the physics and technology of AlxGa1-xN/GaN nanoheterostructures and their potential applications in optoelectronics.
Article
Materials Science, Multidisciplinary
Edy Azrak, Laurent G. Michaud, Alexandre Reinhardt, Samuel Tardif, Marie Bousquet, Nicolas Vaxelaire, Joel Eymery, Frank Fournel, Pierre Montmeat
Summary: The study demonstrates a scalable manufacturing method for transferring crystalline AlN thin-films from silicon wafers onto flexible polymers and discusses the impact of strain engineering on the properties of semiconductor thin-films.
ECS JOURNAL OF SOLID STATE SCIENCE AND TECHNOLOGY
(2021)
Article
Chemistry, Multidisciplinary
Xiang-Dong Tian, Yun Zhang
Summary: In this study, we developed an air-water interface mediated co-assembly strategy to prepare flexible 2D superlattices of Au octahedra with tunable orientations. The self-assembly of Au octahedra into different orientations (face-up, edge-up, and vertex-up) was controlled by the surface wettability of the nanoparticles. The SERS performance of the 2D superlattices was studied, and the vertex-up orientation showed the highest enhancement performance and uniformity.
Article
Engineering, Environmental
Nazar Riswana Barveen, Tzyy-Jiann Wang, Yu-Hsu Chang
Summary: This study reports on a method for synthesizing gold nanostars (Au NSs) with clean surfaces using ethanol and a simple photoreduction process. The synthesized Au NSs are applied on poly(methyl methacrylate) (PMMA) films for surface-enhanced Raman spectroscopy (SERS), showing superior detection performance and multiplex detection ability. The transparent and flexible nature of the Au NSs/PMMA SERS substrate allows for in-situ, real-time detection of multiple antibiotics, potentially improving the detection of antibiotics for global food safety issues.
CHEMICAL ENGINEERING JOURNAL
(2022)
Article
Materials Science, Coatings & Films
Linda Bertel, Rogelio Ospina, Jose Miguel Garcia-Martin, David A. Miranda
Summary: TiO2 thin-films functionalized with specific biomolecules are used to fabricate highly sensitive and selective electrochemical biosensors for disease detection. Among these biosensors, folic acid-functionalized nanomaterials can recognize folate receptors, which are overexpressed in abnormal cells, allowing the detection of tumor cells and photothermal treatment of cancer.
JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A
(2022)
Article
Nanoscience & Nanotechnology
Fabio Isa, James P. Best, Anna Marzegalli, Marco Albani, Christophe Comte, Jamie J. Kruzic, Avi Bendavid
Summary: A novel approach is presented in this paper to tailor the stress properties of diamond thin films through boron doping and micro-fabrication of bridges using focused ion beam milling. Experimental data, supported by detailed confocal micro-Raman investigations and finite element method calculations, suggest that appropriate design of microbridge geometries, together with boron doping, can significantly enhance or diminish material stress compared to non-patterned thin films. This approach, combined with deterministic incorporation and positioning of diamond color centers, may offer new opportunities to tailor the optical and spin properties of diamond-based quantum devices through stress engineering.
Article
Physics, Applied
Kunjalata Majhi, Vivek K. Manu, R. Ganesan, P. S. Anil Kumar
Summary: We investigated the growth of high-quality BiSe thin films on Si (111) substrates at different temperatures using pulsed laser deposition. The sample quality improved as the substrate temperature increased, with BiSe Raman modes emerging at a substrate temperature of 250 degrees C. The modes matched closely with those of single crystals at a substrate temperature of 325 degrees C. By studying the structural properties and Raman modes at each substrate temperature, we identified the optimal condition for growing high-quality BiSe thin films via pulsed laser deposition.
JOURNAL OF APPLIED PHYSICS
(2023)
Article
Materials Science, Multidisciplinary
Ivan Castillo, Karuna Kara Mishra, Ram S. Katiyar
Summary: Vanadium sesquioxide (V2O3) is an important transition metal oxide with potential applications in electronic and memory devices. Thin films of V2O3 were successfully deposited on Si/SiO2/Ti/Pt substrates, exhibiting good crystallinity and composition. The films also showed interesting magnetic behavior at low temperatures. Raman spectroscopy studies provided further insights into the phase transition.
Article
Engineering, Electrical & Electronic
Junhua Yin, Bangdi Zhou, Liang Li, Yao Liu, Wei Guo, Devki N. Talwar, Kaiyan He, Ian T. Ferguson, Lingyu Wan, Zhe Chuan Feng
Summary: The study reports comprehensive spectroscopic analysis of AlN thin films deposited on different surfaces of sapphire substrates, showing that the substrate polarity affects the properties of the films. The AlN film grown on the C-face sapphire has the smallest thickness, band gap, and roughness among the three samples. The temperature-dependent Raman spectra reveal that the AlN film consistently exhibits tensile stress and the effect is most pronounced on the film grown on the C-face sapphire as the temperature increases.
SEMICONDUCTOR SCIENCE AND TECHNOLOGY
(2021)
Article
Polymer Science
Tawanda J. Zimudzi, Sarah E. Sheffield, Kathleen E. Feldman, Peter A. Beaucage, Dean M. DeLongchamp, Douglas Kushner, Christopher M. Stafford, Michael A. Hickner
Summary: The orientation of polyamide thin films on nonporous substrates was investigated using FTIR spectroscopy and NEXAFS measurements. As the number of cycles increases, the orientation of the films gradually becomes isotropic.
Article
Physics, Condensed Matter
Israr ul Haq, Jolly Jacob, Khurram Mehboob, K. Mahmood, A. Ali, Nasir Amin, Salma Ikram, S. Hussain, Yuyi Feng, Fouzia Ashraf
Summary: This research demonstrates the growth of ZnInO thin films through thermal evaporation, forming a ZnInO composite through annealing. The Seebeck coefficient varies at different temperatures, with the highest value at 600 °C.
PHYSICA B-CONDENSED MATTER
(2021)
Article
Chemistry, Physical
T. I. Milenov, I. A. Avramova, A. Dikovska, D. Karaivanova, P. Terziyska, S. K. Kolev, D. Karashanova, B. Georgieva, D. Dimov, V. Atanasov, E. P. Valcheva
Summary: The study found that UV-C irradiation had a significant impact on the structural quality of a-C:H and ta-C:H films, reducing the content of sp(3) and oxygen-containing radicals. The influence of UV-C light directed almost parallel to the films' surface on the structural quality of graphene-like films was slightly higher than that directed perpendicular.
SURFACES AND INTERFACES
(2021)
Article
Materials Science, Multidisciplinary
Thi Huyen Trang Nguyen, Thi Mai Anh Nguyen, Cong Doanh Sai, Thi Hai Yen Le, Thi Ngoc Anh Tran, Thanh Cong Bach, Van Vu Le, Nguyen Hai Pham, An Bang Ngac, Viet Tuyen Nguyen, Thi Ha Tran
Summary: The research combined sputtering and post annealing methods to prepare gold nanoparticles with uniform distribution on cover glass substrates, and studied the effect of gold thickness on the formation of nanoparticles. The study also analyzed the impact of size, inter-distance, and morphology of gold NPs on plasmon properties using SEM and absorption spectroscopy. Different morphologies' enhancement capabilities were verified using FDTD technique, demonstrating the efficient performance of the prepared gold nanoparticles arrays as SERS substrates.
Article
Materials Science, Coatings & Films
Lakshman Srinivasan, Cyril Jadaud, Francois Silva, Jean-Charles Vanel, Jean-Luc Maurice, Erik Johnson, Pere Roca i Cabarrocas, Karim Ouaras
Summary: We successfully grew polycrystalline GaN thin films on Si (100) substrates at room temperature using radiofrequency reactive magnetron sputtering, with Ar and N-2 as the main sputtering and N-atom precursor gas sources, respectively. The effect of working pressure on the thin film's crystalline quality was studied, and it was found that pressures below 50 mTorr result in amorphous films, while pressures above 50 mTorr result in polycrystalline films. The films grown at 50 mTorr exhibited the best crystallinity with a dominant wurtzite hexagonal structure, and a uniform elemental distribution of Ga and N throughout the growth profile.
JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A
(2023)
Article
Chemistry, Multidisciplinary
Zhichen Yan, Rakesh Joshi, Yi You, Geedhika Poduval, John A. Stride
Summary: This study introduces a method for controlled growth of ultrathin carbon films with a structure similar to graphene directly on silicon substrates, which shows potential for producing high-quality graphene films suitable for device fabrication.
Review
Chemistry, Multidisciplinary
Fan Fu, Jia Li, Terry Chien-Jen Yang, Haoming Liang, Antonin Faes, Quentin Jeangros, Christophe Ballif, Yi Hou
Summary: This review focuses on the scientific and technological challenges of monolithic 2-terminal perovskite-silicon tandem solar cells, including factors limiting power conversion efficiency, pathways to achieve higher efficiency, and stability issues. Key areas of research to bring this technology from the lab to industrial production are highlighted.
ADVANCED MATERIALS
(2022)
Article
Energy & Fuels
Frank Meyer, Andrea Ingenito, Juan J. Diaz Leon, Xavier Niquille, Christophe Allebe, Sylvain Nicolay, Franz-Josef Haug, Christophe Ballif
Summary: This work presents the development of passivating contacts for two side contacted c-Si solar cells based on thin interfacial oxide/doped polysilicon. Optimization of layer thickness led to solar cells with high open circuit voltage and fill factor. Localization of the front side passivating contact was achieved through deposition with a shadow mask, resulting in high-efficiency c-Si solar cells with promising efficiency.
SOLAR ENERGY MATERIALS AND SOLAR CELLS
(2022)
Article
Energy & Fuels
Ebrar Oezkalay, Gabi Friesen, Mauro Caccivio, Pierluigi Bonomo, Andrew Fairbrother, Christophe Ballif, Alessandro Virtuani
Summary: Due to restricted rear-side ventilation, building-integrated photovoltaics (BIPV) modules and systems tend to have elevated operating temperatures. A study conducted in Southern Switzerland found that BIPV modules operated at significantly higher temperatures and experienced greater day-night temperature variations compared to modules in an open-rack configuration.
IEEE JOURNAL OF PHOTOVOLTAICS
(2022)
Article
Energy & Fuels
Jean Cattin, Delphine Petri, Jonas Geissbuehler, Matthieu Despeisse, Christophe Ballif, Mathieu Boccard
Summary: The effect of light soaking and forward electric bias treatment on silicon heterojunction solar cells and modules, along with the influence of thermal treatment during lamination, is investigated. It is found that the lamination process can partially reset the improved performance after electric bias or light soaking. However, a second treatment after lamination can improve performance again, leading to similar final performance regardless of the prelamination treatment.
IEEE JOURNAL OF PHOTOVOLTAICS
(2022)
Article
Energy & Fuels
Andrew Fairbrother, Hugo Quest, Ebrar Ozkalay, Philipp Walchli, Gabi Friesen, Christophe Ballif, Alessandro Virtuani
Summary: This study reports on the long-term performance of 55 BIPV systems in Switzerland, finding a median degradation rate of 0.06% per year with significant variation. An algorithm was developed to estimate shading severity in systems experiencing shading issues. It was observed that newer systems have higher shading severity while larger capacity systems have lower shading severity, emphasizing the importance of innovative BIPV module and system design to alleviate shading stresses.
Article
Nanoscience & Nanotechnology
Audrey Morisset, Theodosios Famprikis, Franz-Josef Haug, Andrea Ingenito, Christophe Ballif, Lars J. Bannenberg
Summary: This study investigates the structural evolution of poly-Si contacts using in situ X-ray techniques, revealing the densification and thinning of the poly-Si layer during annealing, as well as the disruption of the thin SiOx layer at high temperature. The results emphasize the importance of controlling high-temperature processes when fabricating c-Si solar cells.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Chemistry, Physical
Ales Vlk, Martin Ledinsky, Andrey Shiryaev, Evgeny Ekimov, Stepan Stehlik
Summary: The bottom-up high-pressure, high-temperature synthesis method allows for unprecedented control over the size of nanodiamonds. In this study, nanodiamonds with sizes ranging from 1.2 to 8 nm were analyzed using multiwavelength Raman spectroscopy. The low-frequency acoustic Raman modes were utilized to determine the size of quantum-sized sub-3 nm nanodiamonds, showing remarkable agreement with other measurement methods such as XRD and HRTEM.
JOURNAL OF PHYSICAL CHEMISTRY C
(2022)
Article
Chemistry, Physical
Jakub Holovsky, Jakub Sebera, Vladimir Sychrovsky, Jan Zemen, Stefaan De Wolf, Christophe Ballif
Summary: In this work, periodic DFT simulations were used to assign vibrational spectra on nanorough wet-processed hydrogenated Si(111) surfaces, providing a better understanding of the imperfect and nanorough Si(111) surfaces through vibrational spectroscopy.
JOURNAL OF PHYSICAL CHEMISTRY C
(2022)
Article
Instruments & Instrumentation
Janina Loeffler, Jonathan Thomet, Samira Frey, Christophe Ballif, Nicolas Wyrsch
Summary: A Monte Carlo model-based study is presented to investigate the dynamic process of electron multiplication in microchannels based on amorphous silicon. The study provides insights into the geometrical limitations and time resolution of amorphous silicon based microchannel plates. The model is implemented in a finite element method simulator to estimate the electron multiplication gain and time response for channels with different geometries. Results show that amorphous silicon based microchannel plates have the potential for ultrafast measurements.
NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT
(2022)
Article
Chemistry, Physical
Esma Ugur, Martin Ledinsky, Thomas G. Allen, Jakub Holovsky, Ales Vlk, Stefaan De Wolf
Summary: The Urbach energy is a metric used to describe the disorder in a semiconductor and can be measured directly using optical techniques. It provides a single value that represents the optoelectronic performance potential of a semiconductor. In solar cells, the Urbach energy has been found to predict the minimal open-circuit-voltage deficit of a material. Considering the Urbach energy in performance calculations gives more realistic limits for power conversion efficiency than classical theories. It is also often correlated with the Stokes shift and carrier mobility of a semiconductor.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2022)
Article
Energy & Fuels
Laurie-Lou Senaud, Gabriel Christmann, Luca Antognini, Antoine Descoeudres, Jonas Geissbuhler, Mathieu Boccard, Sylvain Nicolay, Matthieu Despeisse, Christophe Ballif, Bertrand Paviet-Salomon
Summary: This study investigates and characterizes the electrical losses affecting the collection of photogenerated carriers in silicon heterojunction (SHJ) solar cells. It explores the material properties controlling the physical coupling between the n-type hydrogenated silicon and the transparent conductive oxide (TCO) layers, and develops different material layers to study the device performance. The study also optimizes the multilayers to achieve low series resistance and high passivation.
IEEE JOURNAL OF PHOTOVOLTAICS
(2022)
Article
Energy & Fuels
Andrea Ingenito, Christophe Alleb, Sofia Libraro, Christophe Ballif, Bertrand Paviet-Salomon, Sylvain Nicolay, Juan J. Diaz Leon
Summary: This study demonstrates the use of DC-sputtered poly-Si(n) as a viable option for high-efficiency n-type solar cells. The sputtered poly-Si(n) provides high passivation and low contact resistivity, allowing for increased efficiency. The potential for further optimization is indicated through Quokka simulations.
SOLAR ENERGY MATERIALS AND SOLAR CELLS
(2023)
Article
Energy & Fuels
Laurie-Lou Senaud, Luca Antognini, Gabriel Christmann, Mathieu Boccard, Matthieu Despeisse, Christophe Ballif, Bertrand Paviet-Salomon
Summary: This article applies the transfer length method (TLM) measurements under variable illumination to study p-type carrier selective passivating contacts (CSPCs) in silicon heterojunction (SHJ) technology. The study finds that illumination has a strong impact on the contact resistivity (rho(c)) of p-type CSPCs, similar to what was previously observed in n-type CSPCs. Furthermore, the study demonstrates the different effects of illumination on rho(c) depending on the doping of the p-type hydrogenated silicon layer. The results provide insights for understanding TLM measurements under illumination and investigating carrier transport and electrical losses in CSPC solar cells.
IEEE JOURNAL OF PHOTOVOLTAICS
(2023)
Article
Energy & Fuels
Christophe Allebe, Antoine Descoeudres, Patrick Wyss, Pauline Boillat, Nicolas Pernes, Bertrand Paviet-Salomon, Christophe Ballif
Summary: This study investigates the electrical properties of electron-selective passivating contacts based on thin tunnel oxide capped by a phosphorus-doped poly-Si layer. The impact of different doping methods and parameters on surface passivation and carrier extraction is studied. The study finds that similar levels of implied V-OC and contact resistivity can be achieved with different methods of growing the tunnel oxide. In-situ doping with doped Si targets leads to the same level of passivation and carrier extraction as ex-situ doping with POCl3 or plasma-assisted process. The implementation of such passivating contacts in solar cells leads to improved cell efficiency.
IEEE JOURNAL OF PHOTOVOLTAICS
(2023)
Proceedings Paper
Energy & Fuels
Luca Antognini, Laurie-Lou Senaud, Deniz Turkay, Lison Marthey, Julie Dreon, Bertrand Paviet-Salomon, Matthieu Despeisse, Mathieu Boccard, Christophe Ballif
Summary: In this study, accurate breakdown of series resistance (R-S) in a 2 cm x 2 cm screen-printed solar cell was performed using multiple approaches. Experimental observations differed from theoretical expectations, and the accuracy of different methods in predicting R-S and its trend varied. Practical differences between the methods were discussed and possible improvements were proposed.
11TH INTERNATIONAL CONFERENCE ON CRYSTALLINE SILICON PHOTOVOLTAICS (SILICONPV 2021)
(2022)