Article
Materials Science, Multidisciplinary
Wolfram Witte, Stefan Paetel, Richard Menner, Andreas Bauer, Dimitrios Hariskos
Summary: Crystalline gallium oxide is a promising wide-bandgap semiconductor material suitable for high-frequency and high-power devices, as well as thin-film solar cells. X-ray amorphous gallium oxide deposited by RF magnetron sputtering serves as an n-type buffer layer in solar cells, improving efficiency.
PHYSICA STATUS SOLIDI-RAPID RESEARCH LETTERS
(2021)
Article
Energy & Fuels
Diego A. Garzon, Christian Rossi, Ishwor Khatri, Francesco Soggia, Ihsan Caha, Francis Leonard Deepak, Diego Colombara, Sascha Sadewasser
Summary: The formation of Cd-free Zn1-xSnxOy (ZTO) thin film buffer layers for CIGSe solar cells was studied using chemical bath deposition. By modifying the deposition procedure, flatter ZTO films were obtained with inhibited columnar growth. Increasing the concentration of Sn in the chemical bath resulted in a nontrivial increase in the bandgap. Using a 20% Sn concentration, the CIGSe solar cells achieved similar performance to those with a CdS buffer layer, with a maximum efficiency of 10.4% and an average efficiency of 9%.
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
Materials Science, Multidisciplinary
Yunxiang Zhang, Shishi Xu, Zhichao Mu, Kailu Liu, Jikun Chen, Chenliang Zhou, Yifeng Yao, Xiao Chen, Lin Shi, Zhongjie Wang, Yun Sun, Wei Liu, Qinfang Zhang
Summary: Investigations on the potential of Bi-based materials as buffer layers for efficient CIGS solar cells reveal that BiOX materials possess 2D nanosheet structures and show promising performance. Among the BiOX materials, BiOBr exhibits the highest conversion efficiency due to its similar energy band distribution with CdS.
Article
Materials Science, Multidisciplinary
Mohsen Jahandardoost, Marco Nardone, Theresa Magorian Friedlmeier, Curtis Walkons, Shubhra Bansal
Summary: The degradation of RbF post-deposition-treated (PDT) CIGS solar cells under heat/light/bias stress is evaluated for two different buffers, CdS and Zn(O,S). It was found that CdS buffer devices are relatively stable while Zn(O,S) buffer devices show significant efficiency loss. Device models suggest that increased recombination at the CIGS/Zn(O,S) interface and near interface doping contribute to the degradation in Zn(O,S) buffer devices.
JOURNAL OF MATERIALS RESEARCH
(2022)
Article
Materials Science, Multidisciplinary
Wolfram Witte, Wolfram Hempel, Stefan Paetel, Richard Menner, Dimitrios Hariskos
Summary: This study explores the use of gallium oxide as a substitute material in the buffer or HR layers of CIGS thin-film solar cells and investigates its impact on device performance. Through a series of experiments and treatment methods, the efficiency of the cells was successfully improved.
JOURNAL OF MATERIALS RESEARCH
(2022)
Article
Energy & Fuels
Bing Li, Aimei Zhao, Dongmei Xiang, Zhuo Peng, Yujie Yuan, Yupeng Xing, Liyong Yao, Jinlian Bi, Wei Li
Summary: In this study, an Ag buffer layer was used to eliminate the nonuniform distribution of Cu on Mo, resulting in improved crystallinity and performance of ACIGSe absorber and solar cells.
Article
Chemistry, Physical
Yufan Liu, Bin Li, Xiaoyang Liang, Tao Liu, Shufang Wang, Zhiqiang Li
Summary: This study improves the performance of Sb2Se3 solar cells by preparing CdS:O buffer layers and using CBD-CdS to repair interface damage. Optimizing the composition and phase of the composite buffer allows for the achievement of wide band-gap buffer layers and improvement in device spectra response and JSC, VOC parameters.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Chemistry, Physical
Jakapan Chantana, Bobur Ergashev, Yu Kawano, Yukiko Kamikawa, Shogo Ishizuka, Takashi Minemoto
Summary: CIGSe solar cells were fabricated on SLG substrates with the structure of Al/Ni/sputtered Zn(0.88)Mg(0.12)O:Al TCO/sputtered Zn1-xMgxO 2nd buffer/CdS 1st buffer/CIGSe/Mo/SLG. The impact of CBO2 between CIGSe absorber and Zn1-xMgxO 2nd buffer on cell performance and carrier recombination was investigated experimentally and theoretically. The optimization of CBO2 reduced carrier recombination, improved band bending, and increased the conversion efficiency up to 20.0%. With an antireflective coating layer, the CIGSe solar cell achieved a conversion efficiency of 21.1% with the optimized CBO2.
ACS APPLIED ENERGY MATERIALS
(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
Klaas Bakker, Suzanne Assen, Alix Rasia, Nicolas Barreau, Arthur Weeber, Mirjam Theelen
Summary: This study introduces a model that describes the behavior of Cu(In,Ga)Se-2 (CIGS) cells under reverse bias caused by partial shading. The model considers the low and non-Ohmic leakage current and explains the sharp increase in current observed in the CIGS reverse characteristics using the Fowler-Nordheim tunneling effect. The model has been validated against measurements at different temperatures and illumination intensities, and can describe the dependencies of the reverse bias behavior on both temperature and illumination.
IEEE JOURNAL OF PHOTOVOLTAICS
(2022)
Article
Energy & Fuels
Pedro Anacleto, Carl Hagglund, Wei-Chao Chen, Milan Kovacic, Janez Krc, Marika Edoff, Sascha Sadewasser
Summary: Research reveals that the use of nanostructured hafnium oxide rear passivation layers can improve the performance of ultra-thin Cu(In,Ga)Se-2 solar cells. Experimental results show that solar cells with a 500 nm thick CIGS absorber layer and a 40 nm thick HfO2 passivation layer exhibit enhanced performance in terms of V-oc and J(sc), resulting in an average efficiency increase of 1.2%. Simulation work confirms that the optical properties of ultra-thin CIGS solar cells are minimally affected by the HfO2 passivation layer.
PROGRESS IN PHOTOVOLTAICS
(2022)
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
Jessica de Wild, Gizem Birant, Raghavendran Thiruvallur Eachambadi, Thierry Kohl, Dilara G. Buldu, Guy Brammertz, Jean V. Manca, Marc Meuris, Jef Poortmans, Bart Vermang
Summary: The study investigates the passivation of the Cu(In,Ga)Se-2 (CIGS)/Mo back contact using AlOx to reduce recombination at the interface. It was found that the postdeposition treatment using RbF deteriorates performance due to the formation of an injection barrier at the front and reduced acceptor concentration. Analysis with time-of-flight secondary ion mass spectroscopy revealed higher Na concentration at the AlOx/Mo back contact.
Article
Materials Science, Multidisciplinary
Leiyi Sun, Hui Wang, Ruihu Wang, Zhuo Peng, Baozeng Zhou, Yujie Yuan, Liyong Yao, Jinlian Bi, Yupeng Xing, Wei Li
Summary: In this study, the effect of interfacial recombination on CIGSe solar cells was investigated by using oxygen-doped Mo(OxSe1-x)2. By optimizing the band alignment and adjusting the band gap of the material, the back interface recombination was effectively reduced, leading to an improved performance of the solar cells.