Article
Energy & Fuels
Ryotaro Fukuda, Takahito Nishimura, Akira Yamada
Summary: The behavior of carriers for an electron-beam-induced current (EBIC) evaluation in polycrystalline Cu(In, Ga)Se-2 (CIGS) thin-film solar cells was experimentally and theoretically analyzed. The analysis revealed four features in the EBIC signal profiles of the CIGS layers: peaks at grain boundaries (GBs), narrowed peaks near the surface, shifted peaks near the surface, and double peaks at the GBs and surface. These findings will contribute to a comprehensive understanding of the carrier transport mechanism in polycrystalline CIGS, which is crucial for achieving high-efficiency CIGS solar cells.
PROGRESS IN PHOTOVOLTAICS
(2023)
Article
Multidisciplinary Sciences
Jingwei Chen, Xuan Chang, Jianxin Guo, Qing Gao, Xuning Zhang, Chenxu Liu, Xueliang Yang, Xin Zhou, Bingbing Chen, Feng Li, Jianming Wang, Xiaobing Yan, Dengyuan Song, Han Li, Benjamin S. Flavel, Shufang Wang, Jianhui Chen
Summary: An organic passivation scheme using a passivation agent is developed to repair defects in CIGS solar cells, improving device performance. A transparent conductive passivating (TCP) film, incorporating metal nanowires, is used in solar cells to achieve higher transmittance and sheet resistance. This approach shows promise for passivating CIGS and other compound solar cells.
Article
Energy & Fuels
Jan Keller, Patrick Pearson, Nina Shariati Nilsson, Olof Stolt, Lars Stolt, Marika Edoff
Summary: The study focused on the impact of absorber stoichiometry in ACIGS solar cells with bandgaps greater than 1.40 eV, showing that moving away from AgGaSe2 composition can reduce ordered vacancy compounds, leading to improved device performance. An inverse correlation between V-OC and J(SC) was observed, with capacitance profiling revealing enhanced carrier collection in fully depleted samples. Additionally, the measurement of a solar cell with V-OC = 0.916 V at E-g = 1.46 eV represents the highest reported value for this bandgap to date.
Article
Energy & Fuels
Jan Keller, Hisham Aboulfadl, Lars Stolt, Olivier Donzel-Gargand, Marika Edoff
Summary: This contribution investigates the potential of RbF postdeposition treatment on ACIGS solar cells. It is found that while the open-circuit voltage and short-circuit current density can be improved, the fill factor decreases. However, for some stoichiometric samples, the drop in fill factor can be avoided, resulting in higher efficiencies. Extensive material analysis reveals that the treatment leads to modifications in the absorber layer and restricted diffusion of rubidium. A thin RbInSe2 surface layer is also suggested.
Article
Physics, Applied
Aaron S. Gehrke, David E. Sommer, Scott T. Dunham
Summary: In order to improve the performance of Cu(In,Ga)Se-2 thin-film photovoltaic devices, this study investigates the diffusion pathways of In and Ga. Density functional theory is used to identify the most probable defect complexes and mechanisms, as well as calculate their binding energies and migration barriers. Analytic models and simulations are employed to predict the diffusivity of In and Ga under various conditions.
JOURNAL OF APPLIED PHYSICS
(2023)
Article
Nanoscience & Nanotechnology
Longlong Zeng, Linquan Zhang, Yunfeng Liang, Chunhong Zeng, Zeyu Qiu, Haofeng Lin, Ruijiang Hong
Summary: In this study, a novel low-temperature fabrication strategy of CIGS solar cells using the bismuth (Bi)-doping method is reported, and its growth-promoting mechanism is studied. Bi doping significantly improves grain growth and enhances the efficiency of solar cells. The formation of Cu-Bi-Se compounds promotes the crystallization of CIGS absorbers and enhances carrier transport. Bi doping also increases the open circuit voltage of the solar cells.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Chemistry, Multidisciplinary
Mohit Raghuwanshi, Manjusha Chugh, Giovanna Sozzi, Ana Kanevce, Thomas D. Kuehne, Hossein Mirhosseini, Roland Wuerz, Oana Cojocaru-Miredin
Summary: This study investigates both Cu-poor and Cu-rich CIGS solar cells and shows the superior properties of the internal interfaces of Cu-poor cells, such as p-n junction and grain boundaries, which make them the highest-efficiency devices. By employing a correlative microscopy approach, key factors governing the device performance are discovered.
ADVANCED MATERIALS
(2022)
Article
Energy & Fuels
Mohit Raghuwanshi, Jens Keutgen, Antonio Massimiliano Mio, Hossein Mirhosseini, Thomas D. Kuehne, Oana Cojocaru-Miredin
Summary: The grain boundaries (GBs) in CIGS solar cells are important for their efficiency, especially in cells with polycrystalline absorbers. Previous studies have shown that the traits of GBs in CIGS are directly related to their composition. However, this relationship cannot be determined for twin boundaries (TBs). In this study, high-resolution scanning transmission electron microscopy is used to investigate TBs and their differences, and it is found that electrically neutral TBs are cation-anion terminated, while electrically beneficial TBs are cation-cation terminated. The presence of Cu vacancies near cation-cation TBs leads to a passivated TB and better electron transport.
Article
Energy & Fuels
Takahito Nishimura, Jakapan Chantana, Abdurashid Mavlonov, Yu Kawano, Taizo Masuda, Takashi Minemoto
Summary: The article demonstrates theoretically the high efficiencies under front and rear illuminations for bifacial CIGSe solar cells. Adequate bandgap grading and improvement in CIGSe quality contribute to enhanced device performance under both front and rear illuminations, with the introduction of a rear surface layer additionally reducing carrier recombination and enhancing J(SC) in rear illumination.
Article
Energy & Fuels
Longlong Zeng, Chunhong Zeng, Yunfeng Liang, Ye Yuan, Genghua Yan, Ruijiang Hong
Summary: Molybdenum back contact is crucial for CIGS solar cells. A novel molybdenum oxide preparation method was introduced through oxygen plasma treatment of the molybdenum layer. Back passivation was achieved by forming a reverse p-n junction, and the transport of holes was assisted by the molybdenum oxide's gap states, leading to an efficiency improvement of 34.1% in treated solar cells.
Article
Nanoscience & Nanotechnology
Ha Kyung Park, Yunae Cho, Kihwan Kim, Inyoung Jeong, Jihye Gwak, Jae Ho Yun, William Jo
Summary: Efficient carrier transport is crucial for enhancing the performance of thin-film solar cells. This study investigated the properties of such cells using micro-Raman scattering spectroscopy, Kelvin probe force microscopy, and photoluminescence measurements. The results indicated the importance of reducing open-circuit voltage loss for achieving higher power conversion efficiency.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Nanoscience & Nanotechnology
Ha Kyung Park, Yunae Cho, Kihwan Kim, Inyoung Jeong, Jihye Gwak, Jae Ho Yun, William Jo
Summary: Research on efficient carrier transport for enhancing the performance of thin-film solar cells was conducted. The atomic distributions, microstructures, and defect densities of the devices were investigated to understand the charge transport at the CIGS-CdS interface. The results indicated that reducing open-circuit voltage loss is crucial for improving the power conversion efficiency.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Chemistry, Physical
Qing Gao, Chun Cao, Jianping Ao, Jinlian Bi, Liyong Yao, Jiajia Guo, Guozhong Sun, Wei Liu, Yi Zhang, Fangfang Liu, Wei Li
Summary: The efficiency of CIGSe solar cells was successfully increased by spin-coating an In2S3 thin film on the CIGSe surface in this study. By adjusting the thickness of In2S3 film, the surface bandgap was effectively increased, leading to improved device performance.
APPLIED SURFACE SCIENCE
(2022)
Article
Energy & Fuels
Maximilian Krause, Jose A. Marquez, Sergej Levcenco, Thomas Unold, Olivier Donzel-Gargand, Marika Edoff, Daniel Abou-Ras
Summary: The KF post-deposition treatment can increase Voc by removing Cu-poor, Ag-poor, and Ga-rich regions near the ACIGSe/CdS interface. However, an excessive KF dose may lead to the formation of Cu-poor and K-rich regions near the interface, resulting in a decrease in Voc.
PROGRESS IN PHOTOVOLTAICS
(2022)
Article
Chemistry, Physical
Evandro Martin Lanzoni, Thibaut Gallet, Conrad Spindler, Omar Ramirez, Christian Kameni Boumenou, Susanne Siebentritt, Alex Redinger
Summary: Research shows that measurements of workfunction in typical solar cell absorbers may exhibit artifacts, and exposure to air can alter the contrast of grain boundaries and facets, leading to incorrect interpretations of grain boundary physics. Frequency modulation (FM)-KPFM measurements on absorbers not exposed to air demonstrate minimal band bending at grain boundaries, with facet-related contrast dominating the electronic landscape of the semiconductor surface due to the polycrystalline nature of the absorbers.
Article
Chemistry, Inorganic & Nuclear
Maria Teresa Caldes, Catherine Guillot-Deudon, Angelica Thomere, Margaux Penicaud, Eric Gautron, Philippe Boullay, Martine Bujoli-Doeuff, Nicolas Barreau, Stephane Jobic, Alain Lafond
INORGANIC CHEMISTRY
(2020)
Article
Physics, Applied
Sheng Yang, Samira Khelifi, Guy Brammertz, Leo Choubrac, Nicolas Barreau, Pieter Bolt, Bart Vermang, Johan Lauwaert
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2020)
Article
Chemistry, Multidisciplinary
Mohit Raghuwanshi, Roland Wuerz, Oana Cojocaru-Miredin
ADVANCED FUNCTIONAL MATERIALS
(2020)
Article
Materials Science, Multidisciplinary
Constantinos Hatzoglou, Solene Rouland, Bertrand Radiguet, Auriane Etienne, Gerald Da Costa, Xavier Sauvage, Philippe Pareige, Francois Vurpillot
MICROSCOPY AND MICROANALYSIS
(2020)
Article
Energy & Fuels
Aleksandra Nikolaeva, Maximilian Krause, Norbert Schaefer, Wolfram Witte, Dimitrios Hariskos, Tim Kodalle, Christian A. Kaufmann, Nicolas Barreau, Daniel Abou-Ras
PROGRESS IN PHOTOVOLTAICS
(2020)
Article
Materials Science, Multidisciplinary
Leifeng Zhang, Bertrand Radiguet, Patrick Todeschini, Christophe Domain, Yang Shen, Philippe Pareige
JOURNAL OF NUCLEAR MATERIALS
(2020)
Article
Nanoscience & Nanotechnology
Ruiling Gong, Edy Azrak, Celia Castro, Sebastien Duguay, Philippe Pareige, Pere Roca i Cabarrocas, Wanghua Chen
Summary: Alloying Ge with Sn is a promising way for Si compatible optoelectronics. GeSn nanowires were successfully synthesized via nano-crystallization of a hydrogenated amorphous Ge layer with metal Sn droplets, with different morphologies obtained by changing process conditions. Annealing under Ar plasma favors the elaboration of straight GeSn NWs, while the synthesis of out-of-plane GeSn NWs has been demonstrated by reversing the deposition sequence.
Article
Chemistry, Physical
Ruwen Wang, Etienne Boutin, Nicolas Barreau, Fabrice Odobel, Julien Bonin, Marc Robert
Summary: The challenge of converting CO2 into valuable compounds, such as fuels, using renewable energy sources and sustainable compounds is being addressed through artificial photosynthesis research. One promising approach involves solar-assisted electrochemical processes where electrons are supplied by a photovoltaic cell. A PV-EC system has been developed that can reduce CO2 to CO and then convert it to methanol with limited bias voltage. The efficiency of this CO2-to-CH3OH reaction is around 28% under ideal conditions.
Review
Chemistry, Multidisciplinary
Oana Cojocaru-Miredin, Mohit Raghuwanshi, Roland Wuerz, Sascha Sadewasser
Summary: Cu(In,Ga)Se-2 thin-film solar cells have garnered research interest for their cost efficiency and high cell performance, but the presence of grain boundaries can lead to increased recombination activity, affecting cell efficiency.
ADVANCED FUNCTIONAL MATERIALS
(2021)
Article
Chemistry, Multidisciplinary
Ludovica Guarneri, Stefan Jakobs, Alexander von Hoegen, Stefan Maier, Ming Xu, Min Zhu, Sophia Wahl, Christian Teichrib, Yiming Zhou, Oana Cojocaru-Miredin, Mohit Raghuwanshi, Carl-Friedrich Schoen, Marc Droegeler, Christoph Stampfer, Ricardo P. S. M. Lobo, Andrea Piarristeguy, Annie Pradel, Jean-Yves Raty, Matthias Wuttig
Summary: A new type of metavalent bond has been identified in higher chalcogenides, characterized by unique property combination and unconventional bond breaking. Studies on different compounds have shown sudden changes in multiple properties at critical concentrations, providing a blueprint for exploring the impact of metavalent bonding on materials properties and systematic changes in chemical bonding.
ADVANCED MATERIALS
(2021)
Article
Optics
R. Demoulin, L. Khomenkova, C. Labbe, F. Gourbilleau, C. Castro, P. Pareige, E. Talbot
Summary: The luminescence and structural properties of Pr3+ doped HfSiOx thin layers deposited by magnetron sputtering were investigated in relation to annealing temperatures. The emission from Pr3+ ions in the visible range was observed at temperatures above 950 degrees C, with a new orthorhombic crystalline structure of HfO2 nano-grains appearing at 1050 degrees C, leading to new emission peaks in the infrared range. The evolution of cathodoluminescence signal with annealing treatment was discussed in connection with structural changes.
JOURNAL OF LUMINESCENCE
(2021)
Article
Energy & Fuels
Nicolas Barreau, Olivier Durand, Eugene Bertin, Antoine Letoublon, Charles Cornet, Polyxeni Tsoulka, Eric Gautron, Daniel Lincot
Summary: This study investigates the epitaxial growth of Cu(In,Ga)Se2 films (CIGSe) onto GaP/Si(001) pseudosubstrates using co-evaporation, with GaP thin layer epitaxially grown by Molecular Beam Epitaxy (MBE). Extensive structural characterization of epi-CIGSe is performed through X-ray diffraction and transmission electron microscopy, revealing strong evidence of epitaxial growth of CIGSe on (GaP/Si)(001) and the propagation of twins from the GaP/Si interface through the CIGSe/GaP interface. This research aims to pave the way for future CIGSe/GaP/Si structures for tandem solar cells with c-Si bottom cell and GaP interfacial buffer layer, facilitating high-quality CIGSe epitaxial growth as a thin film top cell absorber.
SOLAR ENERGY MATERIALS AND SOLAR CELLS
(2021)
Article
Chemistry, Physical
Oana Cojocaru-Miredin, Elaheh Ghorbani, Mohit Raghuwanshi, Xiaowei Jin, Dipak Pandav, Jens Keutgen, Reinhard Schneider, Dagmar Gerthsen, Karsten Albe, Roland Scheer
Summary: Research has shown that intense sulphurization processes in Cu(In,Ga)Se-2 thin-film solar cells, combined with Ga-grading, can lead to improved electrical properties of the buffer/absorber heterojunction by reducing p-doping and altering the band diagram. This process results in the formation of a S-rich compound at the absorber surface, ultimately offering new possibilities for synthesizing high-performance Cu(In,Ga)(Se,S)(2) solar cells.
Article
Energy & Fuels
Mohit Raghuwanshi, Jens Keutgen, Antonio Massimiliano Mio, Hossein Mirhosseini, Thomas D. Kuehne, Oana Cojocaru-Miredin
Summary: The grain boundaries (GBs) in CIGS solar cells are important for their efficiency, especially in cells with polycrystalline absorbers. Previous studies have shown that the traits of GBs in CIGS are directly related to their composition. However, this relationship cannot be determined for twin boundaries (TBs). In this study, high-resolution scanning transmission electron microscopy is used to investigate TBs and their differences, and it is found that electrically neutral TBs are cation-anion terminated, while electrically beneficial TBs are cation-cation terminated. The presence of Cu vacancies near cation-cation TBs leads to a passivated TB and better electron transport.
Proceedings Paper
Energy & Fuels
Mohit Raghuwanshi, Jens Keutgen, Roland Wuerz, Oana Cojocaru-Miredin
2020 47TH IEEE PHOTOVOLTAIC SPECIALISTS CONFERENCE (PVSC)
(2020)
