Article
Nanoscience & Nanotechnology
Naoki Higashitarumizu, Shiekh Zia Uddin, Daniel Weinberg, Nima Sefidmooye Azar, I. K. M. Reaz Rahman, Vivian Wang, Kenneth B. B. Crozier, Eran Rabani, Ali Javey
Summary: The photophysics of black phosphorus, an optoelectronic material, was investigated. It was found that the photoluminescence quantum yield initially decreases with decreasing thickness due to enhanced surface carrier recombination, but sharply increases afterwards. Furthermore, black phosphorus exhibits a much lower surface carrier recombination velocity compared to other semiconductors.
NATURE NANOTECHNOLOGY
(2023)
Article
Multidisciplinary Sciences
Ramy El-Bashar, Mohamed Hussein, Salem F. Hegazy, Yehia Badr, B. M. A. Rahman, Kenneth T. Grattan, Mohamed Farhat O. Hameed, Salah S. A. Obayya
Summary: The electrical characteristics of quad-crescent-shaped silicon nanowire solar cells were analyzed numerically to optimize performance, resulting in increased optical absorption and power conversion efficiency. The core-shell junction design showed an improvement of approximately 80% in conversion efficiency due to the high back surface field layer, with minimal impact from nanowire surface recombination compared to the axial junction.
SCIENTIFIC REPORTS
(2022)
Article
Physics, Applied
Xiao Li, Xuezhe Yu, Haotian Zeng, Giorgos Boras, Kai Shen, Yunyan Zhang, Jiang Wu, Kwang Leong Choy, Huiyun Liu
Summary: GaAs nanowire-based metal-semiconductor-metal photodetectors achieve enhanced photoresponsivity and reduced response time through surface treatment and interfacial contact optimization. The design demonstrates good repeatability of dynamic photo-switching characteristics and stability, making GaAs nanowires a promising candidate for high-performance and reliable nano-photodetection in the visible range.
APPLIED PHYSICS LETTERS
(2021)
Article
Nuclear Science & Technology
B. Park, Y. Kim, J. Seo, J. Byun, K. Kim
Summary: This study fabricated radiation detectors using CZT crystals and carried out wet passivation with NaOCl on the Br-etched detectors. It was found that passivation improved the transport property and enhanced the performance of the detectors.
NUCLEAR ENGINEERING AND TECHNOLOGY
(2022)
Article
Energy & Fuels
Archana Sinha, Jiadong Qian, Stephanie L. Moffitt, Katherine Hurst, Kent Terwilliger, David C. Miller, Laura T. Schelhas, Peter Hacke
Summary: Degradation from ultraviolet radiation has become prevalent in the front of solar cells due to the use of UV-transmitting encapsulants. This study examines UV-induced degradation in various commercial crystalline silicon cell technologies and finds that modern cell architectures are more vulnerable to UV damage, leading to a significant decrease in power. Bifacial cells with rear-side exposure show a greater power decrease, indicating that the rear side is more susceptible to UV damage.
PROGRESS IN PHOTOVOLTAICS
(2023)
Article
Chemistry, Multidisciplinary
Mariana Zavarize, Nikolai V. V. Sibirev, Yury Berdnikov, Murilo Moreira, Helio T. Obata, Varlei Rodrigues, Vladimir G. G. Dubrovskii, Monica A. Cotta
Summary: InP nanowires were catalyzed by Au, Ag, and Au-Ag nanoparticles on GaAs substrates with different orientations. Statistical analysis and modeling demonstrated that the ratio of droplet surface density to In precursor flux is critical in controlling nanowire growth mode and orientation. These findings enhance our understanding of planar nanowire vapor-liquid-solid growth and provide tools for controlling III-V nanowire growth on lattice-mismatched substrates.
CRYSTAL GROWTH & DESIGN
(2023)
Article
Energy & Fuels
Naeimeh Mozaffari, The Duong, M. M. Shehata, Anh Dinh Bui, Huyen T. Pham, Yanting Yin, Y. Osorio Mayon, Jianghui Zheng, Md Arafat Mahmud, Grace Dansoa Tabi, Gunther G. Andersson, Lachlan E. Black, Jun Peng, Heping Shen, Thomas P. White, Klaus Weber, Kylie R. Catchpole
Summary: Dimensional engineering technique is an efficient method to improve the performance of perovskite solar cells. This study presents a passivation approach for the perovskite/hole transport layer interface using a mixture of guanidinium and n-octylammonium cations. The dual-cation passivation layer provides higher voltage and efficiency, as well as better stability, with a more hydrophobic and smoother surface.
Article
Energy & Fuels
Andreas Wolf, Julian Egle, Sebastian Mack, Hannes Hoffler, David Herrmann, Sabrina Lohmuller, Joerg Horzel, Andreas Fell
Summary: This study focuses on the effective surface recombination velocity of alkaline textured, Phosphorus-diffused, and thermal SiO2/SiNx passivated surfaces with an emphasis on the impact of the thermal oxidation temperature. By applying a recent calibration procedure for carrier lifetime measurements, precise determination of the dark saturation current density was achieved. Experimental results from various diffusion/oxidation process combinations provide a dataset for revising the parameterization of the effective surface recombination velocity and investigating the impact of oxidation temperature on passivation quality, including the modeling of fixed surface charges.
SOLAR ENERGY MATERIALS AND SOLAR CELLS
(2021)
Article
Physics, Applied
I. R. Hooper, E. Khorani, X. Romain, L. E. Barr, T. Niewelt, S. Saxena, A. Wratten, N. E. Grant, J. D. Murphy, E. Hendry
Summary: In this paper, a new type of silicon-based metamaterial with a tunable electron-hole lifetime is designed, achieved by periodically patterning a dielectric surface passivation layer. The application of these metamaterials as photomodulators is investigated, with switching times depending on photoexcitation intensity, wafer thickness, and carrier lifetime.
JOURNAL OF APPLIED PHYSICS
(2022)
Article
Chemistry, Multidisciplinary
Wipakorn Jevasuwan, Naoki Fukata
Summary: The study simplified the formation of aluminum (Al)-catalyzed silicon nanowires (SiNW) and opened up new possibilities for developing SiNW-based silicon photovoltaic cells.
Article
Chemistry, Physical
Lifan Shen, Huan Qian, Yanbin Yang, Yonghao Ma, Jun Deng, Yongzhe Zhang
Summary: High-quality InGaAs nanowires were synthesized by chemical vapor deposition and their surface was modified using simple wet chemistry. The modified nanowires showed significantly improved photoelectronic properties, with enhanced response time and photocurrent. This study offers important reference values for modulating surface states of ternary and multielement nanowires and improving the performance of nanoscale broadband photodetectors.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Chemistry, Physical
K. H. Girish
Summary: Perovskite solar cells have made significant progress in efficiency, but are still hindered by surface defects and stability issues. Passivating surface defects with organic halide salts can increase carrier lifetime and improve charge collection efficiency, enhancing the overall performance of the cells.
SURFACES AND INTERFACES
(2021)
Article
Chemistry, Multidisciplinary
Sophie L. Pain, Edris Khorani, Tim Niewelt, Ailish Wratten, Marc Walker, Nicholas E. Grant, John D. Murphy
Summary: Incorporation of carrier-selective passivating contacts is crucial for achieving the theoretical power conversion efficiency limit in silicon solar cells. Using plasma-enhanced atomic layer deposition (ALD), we created ultra-thin films that can be chemically enhanced for high-performance contacts. 1 nm thick HfO2 films with negative charge show promising passivation properties, surpassing SiO2 and Al2O3 at equivalent thicknesses. Additional passivation is achieved by applying an Al2O3 capping layer, resulting in a surface recombination velocity (SRV) of 3.5 cm s(-1). Immersion in hydrofluoric acid further improves passivation quality, with stable SRVs < 2 cm s(-1) over 50 days. Chemical enhancement occurs at the dielectric surface and fluorination of the Al2O3 and underlying HfO2 films is observed after just 5 s of HF immersion. The Al2O3 top layer can be thinned down by etching, providing a new route for fabricating highly passivating HfO2-containing nanoscale thin films.
Article
Biochemistry & Molecular Biology
Saltanat B. Ikramova, Zhandos N. Utegulov, Kadyrjan K. Dikhanbayev, Abduzhappar E. Gaipov, Renata R. Nemkayeva, Valery G. Yakunin, Vladimir P. Savinov, Victor Yu Timoshenko
Summary: This study explored the use of silicon nanowires (SiNWs) combined with gold nanoparticles (Au NPs) for surface-enhanced Raman scattering (SERS) of probe molecules. The research found that the filling factor of SiNW arrays controlled the SERS efficiency, with the highest enhancement observed for samples with a porosity of 55%. The results demonstrate the electromagnetic enhancement of SERS through localized surface plasmon resonances in Au-NPs on SiNW surfaces, accompanied by light scattering in the SiNW arrays.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2022)
Article
Chemistry, Inorganic & Nuclear
Y. Kim, J. Ko, J. Byun, J. Seo, B. Park
Summary: CdTe-based detectors suffer from the issue of Te-rich surface layers caused by Br etching. These layers act as trapping centers and additional source of charge carriers, which degrade the transport property of charge carriers and increase the leakage current on the detector's surface. To solve this problem, sodium hypochlorite (NaOCl) was introduced as a passivant, and its effect on Cd0.95Mn0.05Te0.98Se0.02 (CMTS) was investigated. The passivation with NaOCl reduced leakage current, compensated defects, improved transport of charge carriers, decreased charge loss, and enhanced the performance of the CMTS detector.
APPLIED RADIATION AND ISOTOPES
(2023)
Article
Optics
A. Bjelajac, M. Gromovyi, E. Sakat, B. Wang, G. Patriarche, N. Pauc, V Calvo, P. Boucaud, F. Boeuf, A. Chelnokov, V Reboud, M. Frauenrath, J. Hartmann, M. El Kurdi
Summary: GeSn alloys are highly promising materials for the integration of CMOS-compatible lasers using Group-IV materials. This study demonstrates room temperature lasing at up to 300 K by utilizing GeSn microdisk resonators fabricated on a GeSn-On-Insulator platform through strain engineering and a thick layer of high Sn content GeSn.
Article
Physics, Applied
L. Casiez, N. Bernier, J. Chretien, J. Richy, D. Rouchon, M. Bertrand, F. Mazen, M. Frauenrath, A. Chelnokov, J. M. Hartmann, V. Calvo, N. Pauc, V. Reboud, P. Acosta Alba
Summary: In this study, the recrystallization of phosphorus-implanted GeSn layers was investigated using UV-NLA. The optimal annealing conditions were identified, leading to the reconstruction of amorphized Ge0.92Sn0.08 crystal. The recrystallized GeSn layers showed specific structures with localized tin and strain variations. UV-NLA has the advantages of localized annealing and strain reversal, which are important for the integration of GeSn mid-IR photonic devices.
JOURNAL OF APPLIED PHYSICS
(2022)
Article
Nanoscience & Nanotechnology
Mohammed Zeghouane, Hadi Hijazi, Franck Bassani, Gauthier Lefevre, Eugenie Martinez, Thierry Luciani, Pascal Gentile, Vladimir G. Dubrovskii, Bassem Salem
Summary: The influence of liquid droplet composition on Sn incorporation in GeSn nanowires (NWs) grown by the vapor-liquid-solid mechanism was investigated. The addition of different elements to the Au catalyst significantly improved the Sn incorporation. The best growth temperature for achieving long untapered NWs was found to be 400 degrees C.
Article
Engineering, Electrical & Electronic
S. Boubenia, G. Lefevre, M. Legallais, S. Labau, F. Bassani, M. B. Hachemi, G. Ghibaudo, B. Salem
Summary: This study investigates the influence factors of the physical, chemical, and electrical properties of PEALD Al2O3 thin films on a silicon substrate. The results show that the structural, electrical, and chemical properties of the films can be tuned by adjusting the substrate bias. Additionally, the composition of the interfacial layer can be controlled by the applied substrate bias. These findings are important for the application of high-k materials.
SEMICONDUCTOR SCIENCE AND TECHNOLOGY
(2022)
Article
Nanoscience & Nanotechnology
Lama Khalil, Debora Pierucci, Emilio Velez-Fort, Jose Avila, Celine Vergnaud, Pavel Dudin, Fabrice Oehler, Julien Chaste, Matthieu Jamet, Emmanuel Lhuillier, Marco Pala, Abdelkarim Ouerghi
Summary: This study visualizes the presence of a flat band near the Fermi level in the van der Waals WSe2/MoSe2 heterobilayer and confirms the coexistence of different domains with arbitrary twist angles. The strong interlayer hybridization effects are observed, which are further confirmed by complementary micro-Raman spectroscopy measurements.
Article
Chemistry, Physical
Marc Dietrich, Loic Paillardet, Anthony Valero, Mathieu Deschanels, Philippe Azais, Pascal Gentile, Said Sadki
Summary: This study utilizes a fast and simple deposition method to create a pseudocapacitive material based on EDOT-OH on alumina-coated silicon nanowires, displaying remarkable capacitive behavior in aqueous Na2SO4 electrolyte.
Article
Nanoscience & Nanotechnology
Jihene Zribi, Debora Pierucci, Federico Bisti, Biyuan Zheng, Jose Avila, Lama Khalil, Cyrine Ernandes, Julien Chaste, Fabrice Oehler, Marco Pala, Thomas Maroutian, Ilka Hermes, Emmanuel Lhuillier, Anlian Pan, Abdelkarim Ouerghi
Summary: By characterizing the electronic properties of a single layer WS1.4Se0.6 alloy, researchers have discovered its unique anisotropic properties. The alloy exhibits a giant unidirectional Rashba spin splitting and in-plane polarization, which could have wide-ranging applications in future electronic, piezoelectric, and spintronic devices.
Article
Chemistry, Multidisciplinary
Yannick Dufil, Marc Dietrich, Dodzi Zigah, Frederic Favier, Said Sadki, Pascal Gentile, Olivier Fontaine
Summary: This study introduces scanning electrochemical microscopy (SECM) as a new technique for in situ characterization and acceleration of degradation processes of conducting polymers, aiming to study the conjugated/conducting polymer-based nanostructured electrodes used for micro-electrochemical energy storage (MEES).
Article
Materials Science, Multidisciplinary
M. Hadi, S. Pailhes, R. Debord, A. Benamrouche, E. Drouard, T. Gehin, C. Botella, J-L Leclercq, P. Noe, F. Fillot, V. M. Giordano
Summary: PECVD amorphous silicon nitride films are widely used in integrated circuits and have important applications in thermal management. The deposition temperature has a critical influence on the thermal conductivity of the films, leading to a significant decrease followed by an increase within a certain temperature range, which may be attributed to the microstructure and hydrogen desorption in the films.
Article
Chemistry, Multidisciplinary
Clement Lausecker, Bassem Salem, Xavier Baillin, Vincent Consonni
Summary: The formation mechanisms of ZnO nanowires from Au seed layers are investigated for different precursor concentrations, leading to variations in the morphological properties. The thermodynamic properties of the chemical bath play a critical role in the formation of ZnO nanowires. This study provides valuable insights for optimizing the morphology of ZnO nanowires for their integration into piezoelectric devices.
CRYSTAL GROWTH & DESIGN
(2023)
Article
Nanoscience & Nanotechnology
Anis Chiout, Cleophanie Brochard-Richard, Laetitia Marty, Nedjma Bendiab, Meng-Qiang Zhao, A. T. Charlie Johnson, Fabrice Oehler, Abdelkarim Ouerghi, Julien Chaste
Summary: A study has found that the frequency of nanomechanical resonators can be effectively tuned at the nanoscale using a suspended MoS2 membrane heated by the Joule effect, with a significantly larger modulation amplitude compared to other approaches. This research is crucial for fully harnessing the potential of two-dimensional materials.
NPJ 2D MATERIALS AND APPLICATIONS
(2023)
Article
Engineering, Electrical & Electronic
Tarek Spelta, Marc Veillerot, Eugenie Martinez, Denis Mariolle, Roselyne Templier, Nicolas Chevalier, Pedro Fernandes Paes Pinto Rocha, Bassem Salem, Laura Vauche, Berangere Hyot
Summary: This study investigates the effect of inductively coupled plasma reactive ion etching (ICP-RIE) combined with atomic layer etching (ALE) on the Al2O3/GaN interface for MOSc-HEMT devices. The results show an increase of the N/Ga ratio near the interface and the presence of impurities in the etched sample.
SOLID-STATE ELECTRONICS
(2023)
Article
Engineering, Electrical & Electronic
Tarek Spelta, Marc Veillerot, Eugenie Martinez, Nicolas Chevalier, Denis Mariolle, Roselyne Templier, Bassem Salem, Pedro Fernandes Paes Pinto Rocha, Laura Vauche, Sarah Boubenia, Berangere Hyot
Summary: This scientific paper presents a chemical study on different Al2O3/GaN interfaces found in high electron mobility transistors for power electronics. The objective is to overcome the limitation of an oxidized gallium layer that affects the electrical behavior of the semiconductor. The structures were analyzed using ToF-SIMS, M-SIMS, and AFM techniques, and the best experimental conditions were determined.
JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B
(2023)
Article
Chemistry, Multidisciplinary
Lama Khalil, Cyrine Ernandes, Jose Avila, Adrien Rousseau, Pavel Dudin, Nikolai D. Zhigadlo, Guillaume Cassabois, Bernard Gil, Fabrice Oehler, Julien Chaste, Abdelkarim Ouerghi
Summary: In this study, we demonstrate the stable growth of p-type hexagonal boron nitride (h-BN) by using Mg atoms as substitutional impurities. Our experiments involving micro-Raman spectroscopy, nano-ARPES, and KPFM show that Mg-doping significantly alters the electronic properties of h-BN. The Mg dopants shift the valence band maximum and result in a reduced Fermi level difference between pristine and Mg-doped h-BN crystals. This research establishes Mg-doping as a promising method for high-quality p-type doped h-BN films, which are crucial for applications in deep ultraviolet LEDs and wide bandgap optoelectronic devices.
NANOSCALE ADVANCES
(2023)
