Article
Energy & Fuels
David Tweddle, Phillip Hamer, Zhao Shen, Vladimir P. Markevich, Michael P. Moody, Peter R. Wilshaw
Summary: A novel characterization technique combining TKD, APT, and isotopic substitution enables the clear detection and quantification of hydrogen atoms present at crystallographic defects in mc-Si.
PROGRESS IN PHOTOVOLTAICS
(2021)
Article
Chemistry, Multidisciplinary
Qingbin Cai, Zhichao Lin, Wenqi Zhang, Guibin Shen, Xiaoning Wen, Hongye Dong, Xiangning Xu, Dongping Zhu, Cheng Mu
Summary: By adding solid CsCl to PbI2 precursor solutions to adjust the properties of PbI2 membranes, reducing grain boundary defects, the efficiency and stability of perovskite solar cells have been improved. Adding Cs and passivating surface defects further enhanced the power conversion efficiency of the cells.
ACS SUSTAINABLE CHEMISTRY & ENGINEERING
(2021)
Article
Computer Science, Information Systems
Sakhone Pharkphoumy, Vallivedu Janardhanam, Tae-Hoon Jang, Kyu-Hwan Shim, Chel-Jong Choi
Summary: The performance of AlGaN/GaN HEMT devices fabricated on Si and sapphire substrates was investigated. The drain current and breakdown voltage of the HEMT devices were improved after SiO2 passivation, indicating the effectiveness of SiO2 passivation. The AlGaN/GaN HEMT fabricated on the sapphire substrate exhibited better performance characteristics due to high crystalline quality and improved surface.
Article
Energy & Fuels
Andre Augusto, Apoorva Srinivasa, Stuart G. Bowden
Summary: Recent developments in surface passivation technology have enabled the use of less doped substrates in silicon solar cells. In this study, we investigate the impact of bulk resistivity on the performance and reliability of silicon cells. We find that higher resistivities lead to increased breakdown voltages and improved module reliability. Moreover, cells with higher resistivities recover faster after light soaking.
Review
Physics, Applied
Lihui Song, Zechen Hu, Dehang Lin, Deren Yang, Xuegong Yu
Summary: This paper introduces the application of hydrogenation engineering in crystalline silicon solar cells. By deactivating and inducing defects, hydrogenation can significantly improve the efficiency of passivated emitter rear contact, TOPCon, and SHJ solar cells.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2022)
Article
Energy & Fuels
Mario Lehmann, Anatole Desthieux, Nathalie Valle, Audrey Morisset, Philippe Wyss, Santhana Eswara, Tom Wirtz, Andrea Ingenito, Pere Roca i Cabarrocas, Christophe Ballif, Franz-Josef Haug
Summary: This article investigates the effect of various processing steps during the fabrication of c-Si/SiOx/SiCx fired passivating contacts on the silicon bulk lifetime, as well as the kinetics of defect deactivation by hydrogenation. The results show a faster passivation of the surface and a slower passivation of shallow bulk defects. The kinetics of the hydrogenation process is limited by the available hydrogen supply at the c-Si/SiOx interface, rather than by diffusion within the bulk of the wafer.
IEEE JOURNAL OF PHOTOVOLTAICS
(2022)
Article
Chemistry, Physical
Hong Zhang, Feng Li, Shidong Wang, Lisheng Zhong
Summary: The study found that an appropriate thickness of oxide layer on the silicon surface promotes uniform growth of pyramidal nuclei in monocrystalline silicon solar cells, leading to a more even distribution of pyramid sizes and reduced surface reflectivity.
APPLIED SURFACE SCIENCE
(2022)
Article
Energy & Fuels
Yun Jia, Youyang Wang, Xiaobo Hu, Jinjia Xu, Guoen Weng, Xianjia Luo, Shaoqiang Chen, Ziqiang Zhu, Hidefumi Akiyama
Summary: In this study, three types of breakdown phenomena in monocrystalline Si solar cells were observed using the reverse-biased electroluminescence imaging technique. Various methods were applied to diagnose each breakdown mechanism, including combining EL and ReBEL imaging, introducing distributed circuit modeling, analyzing temperature coefficient, Si energy band structure, Baraff theory, and identifying the Zener effect as a possible cause of early breakdown.
Article
Engineering, Electrical & Electronic
Moganapriya Chinnasamy, Rajasekar Rathanasamy, Santhosh Sivaraj, Gobinath Velu Kaliyannan, Manju Sri Anbupalani, Saravana Kumar Jaganathan
Summary: The research focuses on enhancing the power conversion efficiency of silicon solar cells by using antireflective thin-film coatings. The study explores the use of zinc selenide as a coating material to improve light transmittance and increase the solar cell's output efficiency.
JOURNAL OF ELECTRONIC MATERIALS
(2022)
Article
Materials Science, Multidisciplinary
Rocio Barrio, Nieves Gonzalez, Jose Javier Gandia
Summary: This study focuses on the utilization of hydrogenated silicon nitride films in passivating defects in multicrystalline silicon wafers. The research identified key parameters controlling material composition and influencing mass density and hydrogen content. By introducing a hydrogen gas flow, the refractive index and mass density of the films can be enhanced, leading to improved minority-carrier lifetime in wafers. Ultimately, the hydrogenated wafers show potential for application in silicon heterojunction solar cell fabrication, enhancing quality, reducing costs, and increasing sustainability.
Article
Chemistry, Physical
The Duong, Thuan Nguyen, Keqing Huang, Huyen Pham, Sunita Gautam Adhikari, Motiur Rahman Khan, Leiping Duan, Wensheng Liang, Kean Chern Fong, Heping Shen, Anh Dinh Bui, Azul Osorio Mayon, Thien Truong, Grace Tabi, Viqar Ahmad, Sachin Surve, Jingnan Tong, Teng Kho, Thanh Tran-Phu, Teng Lu, Jianghui Zheng, Ulrich W. Paetzold, Uli Lemmer, Anita Ho Baillie, Yun Liu, Gunther Andersson, Thomas White, Klaus Weber, Kylie Catchpole
Summary: In this study, 4-methylphenethylammonium chloride (4M-PEACl) is added into a MA-free perovskite precursor, which greatly improves the bulk quality and surface chemistry of the perovskite. The MA-free perovskite solar cells achieve a steady state efficiency of 23.7% and show excellent light stability. Furthermore, a mechanically stacked perovskite-silicon tandem solar cell with a champion efficiency of 30.3% is obtained using this MA-free composition.
ADVANCED ENERGY MATERIALS
(2023)
Article
Energy & Fuels
Shuai Zou, Lei Xu, Chengkun Wu, Jianming Ding, Lei Zhu, Hua Sun, Xiaoya Ye, Xusheng Wang, Xiaohong Zhang, Xiaodong Su
Summary: The study introduces a method for fabricating submicron-texture multicrystalline silicon wafers using ozonated deionized water (DIO3 water) in the silicon wafer wet cleaning process, which has been successfully applied to manufacture efficient mc-Si PERC solar cells. This novel MCCE approach is simple, low-cost, and eco-friendly, making it an attractive alternative to conventional methods for industrial-scale production.
SOLAR ENERGY MATERIALS AND SOLAR CELLS
(2021)
Article
Energy & Fuels
Saman Jafari, Malcolm Abbott, Daqi Zhang, Jian Wu, Fangdan Jiang, Ziv Hameiri
Summary: Extracting the parameters of efficiency-limiting bulk defects in silicon solar cells is crucial for identifying and eliminating their impact. This study introduces a temperature-dependent Suns-Voc measurement method to extract defect parameters in metalized solar cells and validates its accuracy. The method provides more accurate lifetime measurements and is fast and easy to apply for defect characterization in metalized cells.
SOLAR ENERGY MATERIALS AND SOLAR CELLS
(2022)
Article
Energy & Fuels
Xuping Liu, Jihuai Wu, Tingting Zhang, Deng Wang, Xiao Jin, Bing Xu, Zhen Huang, Dongyu Li, Qinghua Li
Summary: By doping organic molecules and surface modification, both anion and cation defects in the perovskite layer can be simultaneously mitigated, thus enhancing the performance and stability of perovskite solar cells.
Article
Nanoscience & Nanotechnology
Pengfei Wu, Shirong Wang, Jin Hyuck Heo, Hongli Liu, Xihan Chen, Xianggao Li, Fei Zhang
Summary: Here, we introduce a mixed GAI and MAI treatment method by forming a 2D alternating-cation-interlayer (ACI) phase (n = 2) perovskite layer on the 3D perovskite, simultaneously modulating the bulk and interfacial defects in the perovskite films. This treatment leads to suppressed nonradiative recombination, longer lifetime, higher mobility, and reduced trap density, resulting in enhanced device performance up to 24.5% and 18.7% for 0.12 and 64 cm(2) devices, respectively. Furthermore, this MGM treatment can be applied to a wide range of perovskite compositions, making it a general method for preparing efficient perovskite solar cells. The treated devices also show improved stabilities without encapsulation.
NANO-MICRO LETTERS
(2023)
Article
Physics, Applied
Sijun Luo, Lukas Trefflich, Susanne Selle, Ron Hildebrandt, Evgeny Krueger, Stefan Lange, Jingjing Yu, Chris Sturm, Michael Lorenz, Holger Von Wenckstern, Christian Hagendorf, Thomas Hoeche, Marius Grundmann
Summary: This paper reports the heteroepitaxial growth of (00.1)-oriented Zn2GeO4 thin films on c-plane sapphire substrates using pulsed laser deposition. The thin films exhibit [11.0] Zn2GeO4// [11.0] Al2O3 and [1(1) over bar.0] Zn2GeO4//[1(1) over bar.0] Al2O3 in-plane orientation relationships. The measured properties include a rocking curve full width at half maximum of 0.35 degrees, a direct bandgap of 4.9 +/- 0.1 eV, and a defect-related photoluminescence emission centered at 2.62 eV with a FWHM of 0.55 eV. This study enhances our understanding of the physical properties and potential device application of Zn2GeO4 thin films.
APPLIED PHYSICS LETTERS
(2023)
Article
Materials Science, Multidisciplinary
Tillmann Stralka, Michael Bar, Fabian Schoeppach, Susanne Selle, Chang Yang, Holger von Wenckstern, Marius Grundmann
Summary: Current probe atomic force microscopy (cp-AFM) measurements reveal the influence of the textured nature of sputtered gamma-CuI (111) thin films on charge carrier transport. The conductive behaviors of grains and grain boundaries (GBs) are differentiated and correlated, showing a clear difference between them. The time-dependent surface changes, possibly caused by atmospheric oxygen, result in the vanishing of charge carrier transport over time.
PHYSICA STATUS SOLIDI A-APPLICATIONS AND MATERIALS SCIENCE
(2023)
Article
Materials Science, Multidisciplinary
Sofie Vogt, Clemens Petersen, Max Kneiss, Daniel Splith, Thorsten Schultz, Holger von Wenckstern, Norbert Koch, Marius Grundmann
Summary: This study presents the structural and electrical properties of undoped and doped alpha-Ga2O3 thin films grown on m-plane sapphire. An undoped alpha-Ga2O3 buffer layer was introduced to improve crystal quality and stabilize the alpha-phase at lower substrate temperatures. Donor doping with tin and germanium achieved high electron mobilities. Suitable annealing temperature for ohmic Ti/Al/Au layer stacks was identified, while high annealing temperatures deteriorated the electrical properties of the thin films, indicating the need for low temperature contacting procedures for alpha-Ga2O3-based devices.
PHYSICA STATUS SOLIDI A-APPLICATIONS AND MATERIALS SCIENCE
(2023)
Article
Physics, Condensed Matter
Evgeny Krueger, Volker Gottschalch, Gabriele Benndorf, Ron Hildebrandt, Ana Lucia Pereira, Michael S. Bar, Steffen Blaurock, Stefan Merker, Chris Sturm, Marius Grundmann, Harald Krautscheid
Summary: This study presents the epitaxial growth of AgxCu1-xI alloy layers and isolated small crystals on Al2O3 (0001) using the close distance sublimation (CDS) technique. Single-phase gamma-AgxCu1-xI thin films are obtained up to an Ag content of approximately 0.5, with the beta-phase also observed at higher Ag contents. The epitaxial relationships between the deposited AgxCu1-xI layers and the Al2O3 substrate, as well as the structure type, are discussed for different alloy compositions. Additionally, a method for depositing polycrystalline single-phase gamma-AgxCu1-xI thin films for Ag contents up to approximately 0.7 is presented based on the solid-state reaction of AgI layers on Al2O3 (0001) substrate with CuI. Furthermore, it is shown that the near-band-edge emission at 2 K is dominated by excitonic recombination, and the spectral position of the emission profile can be tuned by the alloy composition.
PHYSICA STATUS SOLIDI B-BASIC SOLID STATE PHYSICS
(2023)
Article
Nanoscience & Nanotechnology
Jon Borgersen, Robert Karsthof, Vegard Ronning, Lasse Vines, Holger von Wenckstern, Marius Grundmann, Andrej Yu Kuznetsov, Klaus Magnus Johansen
Summary: Significant resistivity variations have been observed in oxides subjected to low ion doses, which cannot be explained by bulk defects. A comparative study of In2O3-based oxides revealed correlations between resistivity evolution, low ion doses, and UV illumination. The resistivity drops were attributed to oxygen desorption facilitated by irradiation/illumination, as confirmed by post-irradiation exposure to oxygen atmosphere.
Review
Materials Science, Coatings & Films
Laurenz Thyen, Daniel Splith, Max Kneiss, Marius Grundmann, Holger von Wenckstern
Summary: We introduce a new technique, MARS-PLD, for area-selective physical vapor deposition. By using a movable mask, we can selectively mask any desired area on a substrate to create multinary material composition gradients. We demonstrated the capabilities of this method by fabricating material gradients in (Mg,Zn)O thin films and on predefined two-dimensional patterns.
JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A
(2023)
Article
Nanoscience & Nanotechnology
Evgeny Krueger, Michael Seifert, Volker Gottschalch, Harald Krautscheid, Claudia S. Schnohr, Silvana Botti, Marius Grundmann, Chris Sturm
Summary: We studied the excitonic transition energy E-0 and spin-orbit split-off energy Delta(0) of gamma-AgxCu1-xI alloy thin films using reflectivity measurements at temperatures between 20 K and 290 K. The observed bowing behavior of the E-0 transition as a function of alloy composition is explained based on first-principles band structure calculations. The spin-orbit coupling increases with increasing Ag-content, and the temperature-dependent bandgap shift decreases with increasing Ag-content.
Article
Physics, Applied
Andreas Mueller, Sebastian Henn, Evgeny Krueger, Steffen Blaurock, Harald Krautscheid, Marius Grundmann, Chris Sturm
Summary: We report on the photoluminescence emission in copper iodide bulk single crystals induced by two- and three-photon absorption around 1.525eV. The non-linear optical processes were investigated through density-dependent, steady-state, and time-resolved photoluminescence spectroscopy. We observed that the photoluminescence intensity showed an almost parabolic behavior with the excitation power when the excitation energy corresponded to half of the bandgap energy. We also found a cubic contribution that increased with decreasing excitation energy. The ratio between the two- and three-photon absorption cross sections was determined to be approximately 10(-28) cm(2)s.
APPLIED PHYSICS LETTERS
(2023)
Article
Physics, Condensed Matter
Marius Grundmann
Summary: This study revisits the problem of potential, electrical field, and charge density in a space charge region. Using the Boltzmann approximation, an analytical asymptotic solution is obtained. The exact solution can be found by numerically integrating an analytical function. A comparison is made with the popular abrupt (or depletion) approximation, and an analytical approximation is provided. The analytical approximation for potential, electrical field, and charge density in a space charge (depletion) region shows good agreement with the (numerically) exact solution.
PHYSICA STATUS SOLIDI B-BASIC SOLID STATE PHYSICS
(2023)
Article
Instruments & Instrumentation
Michael Lorenz, Holger Hochmuth, Holger von Wenckstern, Marius Grundmann
Summary: Pulsed laser deposition (PLD) is a highly flexible physical growth technique for thin films of functional materials. This article describes a relatively simple and reliable concept of PLD hardware that enables deposition on large areas (up to 4 inches in diameter) and tailored lateral and vertical composition spreads without the need for time-consuming hardware changes. Different PLD approaches have been implemented in various chambers by using specific and correlated computer-controlled movements of the target, substrate, and masks, along with an appropriate target phase composition.
REVIEW OF SCIENTIFIC INSTRUMENTS
(2023)
Article
Nanoscience & Nanotechnology
Fabian Schoeppach, Daniel Splith, Holger von Wenckstern, Marius Grundmann
Summary: In this study, metal-semiconductor field-effect transistor (MESFET) devices based on pulsed laser deposition (PLD) grown In2O3 thin films are reported. These devices exhibit on-off ratios exceeding 6 orders of magnitude and low sub-threshold swing values close to the thermodynamic limit. Oxygen plasma treatment and compensation doping with Mg are used to suppress the accumulation of electrons at the surface of In2O3, which is a major obstacle for its use as an active material in electronic devices.
ADVANCED ELECTRONIC MATERIALS
(2023)