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
Energy & Fuels
Nour El I. Boukortt, Mabrouk Adouane, Rawan AlHammadi
Summary: The research investigated the impact of various factors on ultrathin CIGS solar cell performance, finding that using thin film Al2O3 for rear-passivation can significantly improve cell performance by reducing rear side contact recombination losses. However, poor passivation was observed with high density of positive charge or high contact resistance at the interface. The optimal combination led to achieving the best cell performance.
Article
Energy & Fuels
Latha Marasamy, Aruna-Devi Rasu Chettiar, Francisco de Moure-Flores, Velumani Subramaniam
Summary: The CGI ratio in CIGSe semiconductor plays a crucial role in solar energy conversion. This study demonstrates the impact of varying CGI values on the structural, morphological, and electrical properties of CIGSe, showing significant changes in bandgap energy, crystal diameter, crystal shape, carrier concentration, mobility, and resistivity. The findings suggest that tuning the CGI value through a low-cost solution process can greatly enhance the properties of CIGSe solar cell absorbers.
INTERNATIONAL JOURNAL OF ENERGY RESEARCH
(2021)
Article
Chemistry, Physical
Diego Colombara, Billy J. Stanbery, Giovanna Sozzi
Summary: The commercial attractiveness of Cu(In,Ga) (S,Se)(2) (CIGS) photovoltaics is limited by the research and development gap compared to silicon. Overcoming this gap requires strategic approaches and extensive research and development in both industry and lab scale. However, the technological progress relies on our understanding of diffusion phenomena during and after the absorber growth, particularly in combination with alkali metal doping.
JOURNAL OF MATERIALS CHEMISTRY A
(2023)
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
Energy & Fuels
C. Ossig, N. Pyrlik, R. Carron, G. Fevola, S. Patjens, C. Strelow, J. Flugge, A. Kolditz, J. Siebels, J. Garrevoet, K. Spiers, M. Seyrich, D. Bruckner, J. Hagemann, F. Seiboth, A. Schropp, G. Falkenberg, A. Mews, C. G. Schroer, T. Kipp, M. E. Stuckelberger
Summary: Cost efficiency and defect passivation are the two major challenges for thin-film solar cells. Increasing the Ga/In ratio improves performance but conflicts with economic interests. This study investigates Cu(In,Ga)Se-2 cells and finds that In-rich cells have better performance and more uniform distribution compared to Ga-rich cells. The effect of Rb suggests more effective passivation of structural defects.
JOURNAL OF PHYSICS-ENERGY
(2022)
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
Chemistry, Physical
Christopher P. Muzzillo, Stephen Glynn, Glenn Teeter, Lorelle M. Mansfield
Summary: This study investigates the effect of KF post-deposition treatments (PDTs) on the performance of Cu(In,Ga)Se-2 (CIGS) solar cells using air-free transfer of multiple samples. The results show that KF PDTs can improve cell efficiency, enhance minority carrier lifetime, and modify the alignment of the surface valence band.
ACS APPLIED ENERGY 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
Alexandra M. Bothwell, Siming Li, Rouin Farshchi, Michael F. Miller, Jake Wands, Craig L. Perkins, Angus Rockett, Aaron R. Arehart, Darius Kuciauskas
Summary: In this study, the authors characterized Ag-alloyed chalcopyrite solar cells and related voltage and efficiency improvements to electro-optical characteristics. They reduced the defect density and achieved longer minority carrier lifetimes, which increased the open-circuit voltage. Analysis of charge-carrier dynamics showed that improvements in device architecture and reduction of semiconductor defect densities are two effective strategies to enhance solar cell performance.
Article
Energy & Fuels
Lung-Hsin Tu, Chung-Hao Cai, Chih-Huang Lai
Summary: By forming the ordered vacancy compound phase at the beginning of the selenization process and controlling the Se partial pressure, interlayer TiN thickness, and carrier concentration, a high efficiency of CIGSe solar cells has been achieved.
Article
Energy & Fuels
Pedro Santos, Daniel Brito, Pedro Anacleto, Jose Fonseca, Diana de Brito Sousa, Carlos J. Tavares, Jose Virtuoso, Marina Alves, Ana Perez-Rodriguez, Sascha Sadewasser
Summary: This study investigates the impact of copper stoichiometry on the grain size of sputtered CIGSe absorbers and the efficiency of solar cells. It was found that using a Cu-rich target for sputtering CIGSe films results in larger grain size and better solar cell performance. Additionally, a two-stage process was introduced to further enhance solar cell performance by eliminating unwanted impurities and avoiding toxic etching processes.
IEEE JOURNAL OF PHOTOVOLTAICS
(2021)
Article
Chemistry, Physical
Yu-Han Chang, Romain Carron, Mario Ochoa, Carlota Bozal-Ginesta, Ayodhya N. Tiwari, James R. Durrant, Ludmilla Steier
Summary: The efficiency of Cu(In,Ga)Se-2 solar cells has significantly increased over the years due to engineered bandgap gradient profile and controlled alkali atom incorporation. The impact of Ga-gradient on charge carrier dynamics was investigated, showing a significant effect on carrier mobility and recombination times. Transient absorption spectroscopy (TAS) proved to be a valuable tool in studying the complex composition-graded absorber structure.
ADVANCED ENERGY MATERIALS
(2021)
Article
Energy & Fuels
Aldo Kingma, Frideriki Naziris, Louis Gersant-Poulain, Remi Aninat, Klaas Bakker, Marcel Simor, Mirjam Theelen
Summary: To enhance the bankability of photovoltaics, it is necessary to accurately predict the lifetime and degradation rate of PV modules. This study demonstrates that localized ohmic shunts in CIGS-based PV modules can partially or completely recover when exposed to elevated temperatures and humidity. These findings highlight the importance of regular visual inspection and luminescence testing in quality control.
SOLAR ENERGY MATERIALS AND SOLAR CELLS
(2023)
Article
Chemistry, Physical
Sung-Tae Kim, Vishwa Bhatt, Ye-Chan Kim, Ho-Jung Jeong, Ju-Hyung Yun, Jae-Hyung Jang
Summary: The study demonstrates that Na diffusion can enhance the performance of CIGSe thin-film solar cells by promoting the growth of MoSe2 layer at CIGSe/Mo interface and improving junction properties, leading to an increased photo-conversion efficiency.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Energy & Fuels
Tim Kodalle, Tobias Bertram, Rutger Schlatmann, Christian A. Kaufmann
IEEE JOURNAL OF PHOTOVOLTAICS
(2019)
Article
Chemistry, Physical
Maxim Guc, Tim Kodalle, Ramya Kormath Madam Raghupathy, Hossein Mirhosseini, Thomas D. Kuehne, Ignacio Becerril-Romero, Alejandro Perez-Rodriguez, Christian A. Kaufmann, Victor Izquierdo-Roca
JOURNAL OF PHYSICAL CHEMISTRY C
(2020)
Article
Materials Science, Coatings & Films
Nikolaus Weinberger, David Stock, Christian Alexander Kaufmann, Tim Kodalle, Marc D. Heinemann, Daniel Huber, Martina Harnisch, Andreas Zimmermann, Georg N. Strauss, Roman Lackner
JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A
(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
Chemistry, Physical
Felix Lang, Marko Jost, Kyle Frohna, Eike Kohnen, Amran Al-Ashouri, Alan R. Bowman, Tobias Bertram, Anna Belen Morales-Vilches, Dibyashree Koushik, Elizabeth M. Tennyson, Krzysztof Galkowski, Giovanni Landi, Mariadriana Creatore, Bernd Stannowski, Christian A. Kaufmann, Juergen Bundesmann, Joerg Rappich, Bernd Rech, Andrea Denker, Steve Albrecht, Heinz-Christoph Neitzert, Norbert H. Nickel, Samuel D. Stranks
Article
Energy & Fuels
Tim Kodalle, Hasan A. Yetkin, Alejandra Villanueva Tovar, Tobias Bertram, Reiner Klenk, Rutger Schlatmann, Christian A. Kaufmann
Summary: A comprehensive device model for CIGSe thin-film solar cells based on numerical simulations is presented, which reproduces experimentally determined characteristics under different Rb-conditionings. The model highlights the impacts of Rb-treatment on the doping density, defect passivation, and photocurrent barrier formation within the CIGSe material.
IEEE JOURNAL OF PHOTOVOLTAICS
(2021)
Article
Energy & Fuels
Nikolaus Weinberger, David Stock, Jochen Mesle, Christian A. Kaufmann, Tobias Bertram, Tim Kodalle, Roland Wuerz, Daniel Huber, Andreas Zimmermann, Georg Strauss, Roman Lackner
Summary: This article presents a method for industrial roll-to-roll deposition of Cu(In,Ga)Se-2 thin films on stainless steel foil for use in flexible thin-film solar cells, achieving high conversion efficiency. The influence of different power settings of magnetron sputtering sources on gallium distribution and differences between static and R2R processes are studied.
IEEE JOURNAL OF PHOTOVOLTAICS
(2021)
Article
Nanoscience & Nanotechnology
Nikolaus Weinberger, Tim Kodalle, Tobias Bertram, Rene Gunder, Andreas Saxer, Roman Lackner, Georg N. Strauss, Christian A. Kaufmann
Summary: In this study, Rb, In, and Se were deposited at various substrate temperatures, with RbInSe2 crystal phase detectable at 350 degrees C. Crystallization of monoclinic RbInSe2 was observed at 215 degrees C on the sample grown at the lowest temperature. The morphology of the layers and the preferred crystal orientation of the RISe layer changed with increasing substrate temperature.
SCRIPTA MATERIALIA
(2021)
Article
Chemistry, Multidisciplinary
Anna Andrle, Philipp Hoenicke, Grzegorz Gwalt, Philipp-Immanuel Schneider, Yves Kayser, Frank Siewert, Victor Soltwisch
Summary: The article introduces a novel characterization technique based on X-ray fluorescence measurements, utilizing the X-ray standing wave field as a nanoscale sensor for nanostructures, aiming to achieve high sensitivity and non-destructive characterization of nanostructures.
Article
Green & Sustainable Science & Technology
Bunyamin Umsur, Natalia Maticiuc, Tim Kodalle, Robert Wenisch, Isheta Majumdar, Yajie Wang, Hasan A. Yetkin, Tobias Bertram, Christian A. Kaufmann, Rutger Schlatmann, Iver Lauermann
Summary: This paper compares the properties of CdS/CIGSe and Zn(O,S)/CIGSe interfaces depending on the absorber composition and the application of an RbF post deposition treatment. It was found that Zn(O,S)/CIGSe interface is less sensitive to changes of the CIGSe composition and to the RbF-PDT compared to the CdS/CIGSe interface. Additionally, the study revealed a strong correlation of Cd diffusion and concentration of VCu in CIGSe before the PDT.
Article
Energy & Fuels
Sinju Thomas, Tobias Bertram, Christian Kaufmann, Tim Kodalle, Jose A. Marquez Prieto, Hannes Hempel, Leo Choubrac, Wolfram Witte, Dimitrios Hariskos, Roland Mainz, Romain Carron, Jan Keller, Pablo Reyes-Figueroa, Reiner Klenk, Daniel Abou-Ras
Summary: In this study, the impacts of effective band-gap energy, electron diffusion length, and Ga/In gradient on the Gaussian broadening of parameters describing the EQE onset of thin-film solar cells were evaluated. The results show that the total standard deviation sigma(total) can be separated into contributions from these material properties and a residual component sigma(residual). It is demonstrated that a flat band-gap with no compositional gradient in the CIGSe absorber is essential to obtain the lowest sigma(total) values and thus result in lower recombination losses and gains in V-oc.
PROGRESS IN PHOTOVOLTAICS
(2022)
Article
Chemistry, Multidisciplinary
Ivona Kafedjiska, Igal Levine, Artem Musiienko, Natalia Maticiuc, Tobias Bertram, Amran Al-Ashouri, Christian A. Kaufmann, Steve Albrecht, Rutger Schlatmann, Iver Lauermann
Summary: The performance of five hole-transporting layers (HTLs) in single-junction perovskite and Cu(In, Ga)Se-2 (CIGSe)-perovskite tandem solar cells was investigated. Among them, NiOx:Cu+SAM was found to be the most suitable HTL for the monolithic CIGSe-perovskite tandem devices. It exhibited superior interfacial charge-carrier dynamics and achieved a power-conversion efficiency of 23.4%, V-oc of 1.72V, and a fill factor of 71%.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Article
Energy & Fuels
I Kafedjiska, G. Farias Basulto, F. Ruske, N. Maticiuc, T. Bertram, C. A. Kaufmann, R. Schlatmann, I Lauermann
Summary: We propose monolithic copper-indium-gallium-diselenide (Cu(In,Ga)Se-2, CIGSe)-perovskite tandem solar cells with NiOx:Cu as a hole-transporting layer (HTL) transferred in air or N-2. The tandem with N-2-transferred NiOx:Cu + SAM achieves a champion efficiency of 23.2%, V-oc of 1.69 V, and FF of 78.3%. Air-transferred NiOx:Cu + SAM samples exhibit V-oc and FF losses, while those without SAM have heavy shunts. Exposure to air leads to loss in Ni2+ species, changes in NiOx:Cu's work function and valence band maxima, negatively impacting the tandems' V-oc and FF. Various morphological defects are detected in tandems with poor performance, originating from defects in the bottom CIGSe cell or cracking/delaminating of the perovskite top cell. The NiOx:Cu + SAM HTL bi-layer can decouple the growth of the top device from the rough, defect-rich and defect-tolerant bottom device, enabling high-performing devices.
JOURNAL OF PHYSICS-ENERGY
(2023)
Article
Materials Science, Multidisciplinary
Amala Elizabeth, Hauke Conradi, Sudhir K. Sahoo, Tim Kodalle, Christian A. Kaufmann, Thomas D. Kuehne, Hossein Mirhosseini, Daniel Abou-Ras, Harry Moenig
Article
Energy & Fuels
Alejandra Villanueva-Tovar, Tim Kodalle, Christian A. Kaufmann, Rutger Schlatmann, Reiner Klenk
