Review
Chemistry, Physical
Atta Ur Rehman, Muhammad Nadeem, Muhammad Usman
Summary: This article provides an overview of the Passivated Emitter and Rear Totally Diffused (PERT) solar cell, which is considered a promising candidate in the field of photovoltaics. The review focuses on the experimental approach towards monofacial PERT cells, discussing the historical overview, cell structure, passivation scheme, contacts formation, light trapping, and antireflection coating scheme.
Article
Engineering, Electrical & Electronic
Cui Liu, Ning Yang, Xiao Yuan
Summary: The study focused on the partial morphology-damaged laser boron doping technique and novel passivated emitter and rear locally diffused (PERL) silicon solar cells. By applying multiple laser scanning, the surface p + concentration was increased, resulting in enhanced local back surface field (BSF) and improved efficiency of the solar cells.
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
(2021)
Article
Energy & Fuels
Dongjin Choi, HyunJung Park, Soohyun Bae, Seung Hyun Shin, Hyebin Han, Bernhard Kloeter, Donghwan Kim, Hae-Seok Lee, Yoonmook Kang
Summary: This study investigates effective contact formation during low-temperature firing with applied current in Si solar cells. By applying a current during firing, contact resistance was reduced and SiNx etching was enhanced, resulting in improved device efficiency.
SOLAR ENERGY MATERIALS AND SOLAR CELLS
(2022)
Article
Energy & Fuels
Lihui Song, Zechen Hu, Lingxin Fang, Yongmei Cai, Sheng He, Haiyan Huang, WeiChih Hsu, Xuegong Yu, Deren Yang
Summary: The two-step postfiring bias treatment can significantly enhance the efficiency of commercial gallium-doped PERC solar cells by up to 0.1%, with positive biasing followed by negative biasing resulting in an average efficiency enhancement of around 0.05% each. A new model involving hydrogen behavior under electric field is proposed to explain the mechanism behind the efficiency improvement from the bias treatments.
Article
Energy & Fuels
Tian Pu, Honglie Shen, Kuang Hong Neoh, Fei Ye, Quntao Tang
Summary: The industrially proven method for increasing cell efficiency involves sandwiching a layer of SiOx/SiOxNy between AlOx and SiNx in the rear passivation stack. By optimizing the parameters of different materials, efficiency gains can be achieved, particularly by adjusting the thickness of SiOx film and the refractive index of SiOxNy film.
Article
Materials Science, Coatings & Films
Gamze Koekbudak, Ahmet E. Kececi, Hisham Nasser, Rasit Turan
Summary: The study investigated the passivation quality of ultra-thin Al2O3 on Cz p-type wafers for PERC solar cells. Results showed that ultra-thin Al2O3 thicknesses can provide superior passivation quality compared to commonly applied larger thicknesses, offering potential for cost reduction and efficiency improvements in industrial PERC solar cells.
JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A
(2021)
Article
Environmental Studies
Virender Sharma, Hrishikesh Dhasmana, Abhishek Verma, Avshish Kumar, C. Kannan, Yash Pal, Shivangi Jha, V. K. Jain
Summary: This study investigates enhanced surface passivation in the existing industrial process line of large area n-type silicon solar cells. The researchers optimize the Rapid Thermal Process (RTP) in the temperature range of 500-900 degrees C and evaluate the devices with respect to regularly processed solar cells. They find that annealing with hydrogenation from a silicon nitride layer improves surface passivation, resulting in significant improvements in effective minority carrier lifetime, implied open circuit voltage, and surface recombination velocity.
ENERGY & ENVIRONMENT
(2023)
Article
Energy & Fuels
Stephan Maus, Felix Maischner, Stephan Riepe, Johannes Greulich, Elmar Lohmuller, Florian Schindler, Pierre Saint-Cast, Patricia Krenckel, Adam Hess, Sabrina Lohmuller, Andreas Wolf, Ralf Preu
Summary: This study examines boron-doped cast-monocrystalline silicon wafers fabricated using the Seed Manipulation for ARtificially controlled defect Technique (SMART mono-Si) for passivated emitter and rear cell (PERC) fabrication. The research found that SMART mono-Si PERCs exhibit almost the same performance as traditional Cz-Si PERCs. Additionally, the investigation showed that the minority charge carrier bulk lifetime of SMART mono-Si wafers remains high after different high-temperature process steps in the PERC process flow.
Article
Engineering, Electrical & Electronic
Chih Cheng Yang, Sheng Yao Chou, Min Chen Chen, Shih Kai Lin, Sung Yu Chen, Shui Chin Liu, Kao Yuan Wang, Tsung Ming Tsai, Jen Wei Huang, Ting Chang Chang
Summary: The use of supercritical fluid as a low temperature defect passivation technology to enhance PERC solar cell performance was investigated in this study. Electronic analysis confirmed the benefits of the SCF treatment on solar cell properties. A proposed model explained how the SCF treatment passivates interface defects and improves device performance.
MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING
(2022)
Article
Energy & Fuels
Tian Pu, Honglie Shen, Kuang Hong Neoh, Kai Gao, Fei Ye
Summary: This study successfully reduced the reflectance of a c-Si wafer surface and improved the passivation effect by preparing the NH structure. The NH structure, prepared using metal-assisted chemical etching and nanostructure rebuilding methods, showed great potential for mass production of monocrystalline silicon cells.
Article
Energy & Fuels
Ying-Yuan Huang, Young-Woo Ok, Keeya Madani, Wookjin Choi, Ajay Upadhyaya, Vijay Upadhyaya, Brian Rounsaville, Vinodh Chandrasekaran, Ajeet Rohatgi
Summary: Understanding and optimizing ion-implanted boron emitters combined with screen printed contacts can lead to very low recombination current density and high-efficiency solar cells with rear poly-Si/SiO2 passivated contacts. By engineering emitter profiles and dielectric passivation, as well as optimizing paste chemistry and firing conditions, it is possible to reduce recombination under metal contacts and in passivated regions, ultimately improving overall efficiency potential.
SOLAR ENERGY MATERIALS AND SOLAR CELLS
(2021)
Article
Energy & Fuels
Nicholas E. Grant, Pietro P. Altermatt, Tim Niewelt, Regina Post, Wolfram Kwapil, Martin C. Schubert, John D. Murphy
Summary: Czochralski-grown gallium-doped silicon wafers are commonly used for commercial PERC devices due to their enhanced stability. The carrier lifetime of these wafers can reach into the millisecond region without additional processing, showing an advantage over boron-doped silicon. The stability of gallium-doped PERC cells under illumination varies, with some cells exhibiting degradation and recovery resembling LeTID, while others remain stable.
Article
Chemistry, Multidisciplinary
Antonio Oliveira, Marco Curado, Jennifer Teixeira, Daniela Tome, Ihsan Caha, Kevin Oliveira, Tomas Lopes, Margarida Monteiro, Andre Violas, Maria Correira, Paulo Fernandes, Francis Deepak, Marika Edoff, Pedro Salome
Summary: A decentralized energy system requires photovoltaic solutions that meet new aesthetic paradigms and address materials shortages. Interface passivation is a strategy to reduce absorber thickness and improve efficiency, but a deeper understanding is needed to bridge the gap between ultra-thin devices and mono-Si. A comparison between a passivated ultra-thin solar cell and a conventional nonpassivated counterpart showed significant differences in charge carrier dynamics, with the passivated device demonstrating lower recombination rates and improved efficiency.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Article
Energy & Fuels
Ashok Kumar Sharma, Suchismita Mitra, Siddharth Behera, Prabir K. Basu
Summary: The study focuses on reducing losses at the rear surface of PERC solar cells through process optimization, with spreading resistance and reverse saturation current density identified as key parameters for efficiency improvement. The research suggests a potential increase of 1.29% in power conversion efficiency by selecting appropriate wafer resistivity and improving passivation uniformity across the solar cell area.
SOLAR ENERGY MATERIALS AND SOLAR CELLS
(2021)
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
Materials Science, Multidisciplinary
Bernd Steinhauser, Frank Feldmann, Daniel Ourinson, Henning Nagel, Tobias Fellmeth, Martin Hermle
PHYSICA STATUS SOLIDI A-APPLICATIONS AND MATERIALS SCIENCE
(2020)
Article
Materials Science, Multidisciplinary
Varun Arya, Bernd Steinhauser, Benjamin Gruebel, Christian Schmiga, Norbert Bay, Damian Brunner, Michael Passig, Andreas A. Brand, Sven Kluska, Jan Nekarda
PHYSICA STATUS SOLIDI A-APPLICATIONS AND MATERIALS SCIENCE
(2020)
Article
Energy & Fuels
Bernd Steinhauser, Armin Richter, Andreas Fell, Martin Hermle
Summary: The implied voltage iV(OC) is a crucial parameter for evaluating the electronic quality of solar cell test samples, but it can be significantly influenced by various factors such as sample properties and interface quality. This study demonstrates that even minor changes in sample properties can result in a notable deviation in iV(OC), and when multiple influences are combined, this difference can further amplify.
IEEE JOURNAL OF PHOTOVOLTAICS
(2021)
Article
Energy & Fuels
Benjamin Gruebel, Gisela Cimiotti, Christian Schmiga, Varun Arya, Bernd Steinhauser, Norbert Bay, Michael Passig, Damian Brunner, Markus Glatthaar, Sven Kluska
Summary: The study demonstrates a lead-free metallization approach for bifacial tunneling oxide and passivating contacts (TOPCon) solar cells without the need for an initial metal seed layer, achieved by electroplating Ni/Cu/Ag. The method allows for narrow contact geometries and low contact resistivity, addressing challenges such as direct contacting of silicon and dissolution of contacts. An optimized process sequence resulted in a solar cell efficiency of 22.5% on industrial bifacial TOPCon solar cells, matching the performance of screen-printed reference solar cells.
IEEE JOURNAL OF PHOTOVOLTAICS
(2021)
Article
Energy & Fuels
Armin Richter, Ralph Muller, Jan Benick, Frank Feldmann, Bernd Steinhauser, Christian Reichel, Andreas Fell, Martin Bivour, Martin Hermle, Stefan W. Glunz
Summary: Front- and back-junction silicon photovoltaics dominate the market due to lower manufacturing complexity, but achieving efficiency improvements remains challenging. An optimized design by Richter et al. has led to a 26.0%-efficient cell. While interdigitated back-contact cells offer the highest efficiency, both-sides-contacted cells are preferred in industrial production for their simplicity.
Article
Materials Science, Multidisciplinary
Benjamin Grubel, Henning Nagel, Bernd Steinhauser, Frank Feldmann, Sven Kluska, Martin Hermle
Summary: Reducing the thickness of poly-Si significantly increases shunt resistance, reduces reverse bias current, and lowers the risk of hot spots in solar cells. Electroplated metallization is a more suitable option for contacting thin TOPCon layers compared to screen-printed metallization.
PHYSICA STATUS SOLIDI A-APPLICATIONS AND MATERIALS SCIENCE
(2021)
Article
Energy & Fuels
AnYao Liu, Zhongshu Yang, Frank Feldmann, Jana-Isabelle Polzin, Bernd Steinhauser, Sieu Pheng Phang, Daniel Macdonald
Summary: The paper presents a method to separately quantify the impact of each component on the overall gettering effect of poly-Si/SiOx passivating contact structures. Experimental and simulation results confirm the heavily doped poly-Si layer acts as the main gettering sink, while the presence of different SiOx interlayers determines the overall gettering rate. Different SiOx interlayers demonstrate varying degrees of blocking effects on impurity diffusion.
SOLAR ENERGY MATERIALS AND SOLAR CELLS
(2021)
Article
Energy & Fuels
Andreas Fell, Tim Niewelt, Bernd Steinhauser, Friedemann D. Heinz, Martin C. Schubert, Stefan W. Glunz
Summary: This study comprehensively reassesses and quantifies the influences on radiative recombination in silicon for photovoltaic applications, proposes a new PR model, and emphasizes the importance of a deeper understanding of radiative recombination.
SOLAR ENERGY MATERIALS AND SOLAR CELLS
(2021)
Article
Energy & Fuels
Bernd Steinhauser, Tim Niewelt, Armin Richter, Rebekka Eberle, Martin C. Schubert
Summary: Recent advancements in surface passivation technology and wafer pretreatment have significantly improved the achievable minority charge carrier lifetime in crystalline silicon. The main limitation identified in this study is likely caused by silicon bulk recombination, possibly due to impurities. Despite these limitations, the measured lifetimes on p-type and n-type crystalline silicon wafers exceed previously reported values.
Article
Energy & Fuels
Stefan W. Glunz, Bernd Steinhauser, Jana-Isabelle Polzin, Christoph Luderer, Benjamin Gruebel, Tim Niewelt, Asmaa M. O. M. Okasha, Mathias Bories, Henning Nagel, Katrin Krieg, Frank Feldmann, Armin Richter, Martin Bivour, Martin Hermle
Summary: This paper provides an overview of the potential of passivating contacts based on poly-Si/SiOx structures known as TOPCon in improving the efficiency of crystalline silicon solar cells. It discusses the historical development of such contact structures and describes the current state-of-the-art in laboratory and industry. The paper also addresses four different research topics related to TOPCon technology, including re-parametrization of recombination in silicon, control of dopant diffusion, single-sided deposition of the poly-Si layer, and the fabrication of silicon-based tunnel junctions for perovskite-silicon tandem cells.
PROGRESS IN PHOTOVOLTAICS
(2023)
Article
Energy & Fuels
Zohreh Kiaee, Tobias Fellmeth, Bernd Steinhauser, Christian Reichel, Milad Nazarzadeh, Ann-Catherine Noelken, Roman Keding
Summary: In this article, the authors evaluate an alternative method for the formation of selectively doped n-type tunnel oxide passivating contacts (n-TOPCon) using inkjet-printing. The study shows that inkjet-printing of phosphorus dopants can achieve excellent surface passivation and fulfill the requirement of low contact resistance. The authors also confirm the suitability of the ink and inkjet processes for integration in TOPCon solar cells based on the performance evaluation of the prepared solar cells.
IEEE JOURNAL OF PHOTOVOLTAICS
(2022)
Article
Materials Science, Multidisciplinary
Bernd Steinhauser, Varun Arya, Leonie Jakob, Friedemann D. Heinz, Christian Schmiga, Benjamin Gruebel, Andreas A. Brand, Sven Kluska, Jan F. Nekarda
Summary: This study presents an analysis on the impact of laser contact opening of TOPCon/SiNx stacks. By etching in tetramethylammonium hydroxide (TMAH), the defect distribution in the interfacial tunnel oxide is accessed and analyzed. The findings show that the defect density significantly increases in areas where adjacent laser contact openings overlap. Furthermore, the investigations reveal that defects in the interfacial oxide are mainly created along exposed structures like tips and edges of (etched-back) pyramids. Comparison of TOPCon/SiNx stacks with different TOPCon thicknesses also indicates that etch pits and defect density related to laser contact opening become more significant at lower thicknesses.
PHYSICA STATUS SOLIDI A-APPLICATIONS AND MATERIALS SCIENCE
(2022)
Article
Energy & Fuels
Marion Driesen, Armin Richter, Jana-Isabelle Polzin, Frank Feldmann, Bernd Steinhauser, Markus Ohnemus, Charlotte Weiss, Jan Benick, Stefan Janz
Summary: In this article, a simplified processing method for n-type silicon-based TOPCon solar cells is proposed by reducing the number of high temperature processes. Rapid vapor-phase direct doping (RVD) technology is used for simultaneous emitter formation and annealing of the TOPCon layers. The optimized solar cells exhibit high efficiency and low contact resistance.
IEEE JOURNAL OF PHOTOVOLTAICS
(2022)
Article
Energy & Fuels
Benjamin Hammann, Bernd Steinhauser, Andreas Fell, Regina Post, Tim Niewelt, Wolfram Kwapil, Andreas Wolf, Armin Richter, Hannes Hoeffler, Martin C. Schubert
Summary: The recombination parameter J(0)(s) is essential for characterizing surface recombination, and its calculation requires various methods and models. This study investigates the impact of recent revisions to the models for Auger and radiative recombination in crystalline silicon on J(0)(s). It provides a detailed explanation of the origin and potential methods for obtaining J(0)(s) from effective lifetime measurements and simulations, including fitting the full lifetime curve and a novel approach based on reparameterizing the excess charge carrier density ?n.
IEEE JOURNAL OF PHOTOVOLTAICS
(2023)
Proceedings Paper
Energy & Fuels
Oliver John, Gernot Emanuel, Jan Paschen, Angela De Rose, Bernd Steinhauser, Andreas Brand, Jan Nekarda
2020 47TH IEEE PHOTOVOLTAIC SPECIALISTS CONFERENCE (PVSC)
(2020)
