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4. Texture Formation in Polycrystalline Thin Films of All-Inorganic Lead Halide Perovskite

Author

Steele, Julian A., Solano, Eduardo, Jin, Handong, Prakasam, Vittal, Braeckevelt, Tom, Yuan, Haifeng, Lin, Zhenni, de Kloe, René, Wang, Qiong, Rogge, Sven M. J., Van Speybroeck, Veronique, Chernyshov, Dmitry, Hofkens, Johan, and Roeffaers, Maarten B. J.

Subjects
Condensed Matter - Materials Science
Abstract

Controlling grain orientations within polycrystalline all-inorganic halide perovskite solar cells can help increase conversion efficiencies toward their thermodynamic limits, however the forces governing texture formation are ambiguous. Using synchrotron X-ray diffraction, we report meso-structure formation within polycrystalline CsPbI2.85Br0.15 powders as they cool from a high-temperature cubic perovskite ({\alpha}-phase). Tetragonal distortions (\b{eta}-phase) trigger preferential crystallographic alignment within polycrystalline ensembles, a feature we suggest is coordinated across multiple neighboring grains via interfacial forces that select for certain lattice distortions over others. External anisotropy is then imposed on polycrystalline thin films of orthorhombic ({\gamma}-phase) CsPbI3-xBrx perovskite via substrate clamping, revealing two fundamental uniaxial texture formations; (i) I-rich films possess orthorhombic-like texture (<100> out-of-plane; <010> and <001> in-plane), while (ii) Br-rich films form tetragonal-like texture (<110> out-of-plane; <1-10> and <001> in-plane). In contrast to relatively uninfluential factors like the choice of substrate, film thickness and annealing temperature, Br incorporation modifies the {\gamma}-CsPbI3-xBrx crystal structure by reducing the orthorhombic lattice distortion (making it more tetragonal-like) and governs the formation of the different, energetically favored textures within polycrystalline thin films., Comment: Supporting information attached to end of document. Work has been accepted

Published
2020

7. An embedded interfacial network stabilizes inorganic CsPbI3 perovskite thin films

Author

Steele, Julian A., Braeckevelt, Tom, Prakasam, Vittal, Degutis, Giedrius, Yuan, Haifeng, Jin, Handong, Solano, Eduardo, Puech, Pascal, Basak, Shreya, Pintor-Monroy, Maria Isabel, Van Gorp, Hans, Fleury, Guillaume, Yang, Ruo Xi, Lin, Zhenni, Huang, Haowei, Debroye, Elke, Chernyshov, Dmitry, Chen, Bin, Wei, Mingyang, Hou, Yi, Gehlhaar, Robert, Genoe, Jan, De Feyter, Steven, Rogge, Sven M. J., Walsh, Aron, Sargent, Edward H., Yang, Peidong, Hofkens, Johan, Van Speybroeck, Veronique, and Roeffaers, Maarten B. J.

Published
2022
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9. 3D‐cavity‐confined CsPbBr3 quantum dots for visible‐light‐driven photocatalytic C(sp3)–H bond activation.

Author

Gao, Yu‐Jie, Jin, Handong, Esteban, Daniel A., Weng, Bo, Saha, Rafikul A., Yang, Min‐Quan, Bals, Sara, Steele, Julian A., Huang, Haowei, and Roeffaers, Maarten B. J.

Subjects
QUANTUM dots, MESOPOROUS silica, STRUCTURAL stability, METAL halides, PEROVSKITE
Abstract

Metal halide perovskite (MHP) quantum dots (QDs) offer immense potential for several areas of photonics research due to their easy and low‐cost fabrication and excellent optoelectronic properties. However, practical applications of MHP QDs are limited by their poor stability and, in particular, their tendency to aggregate. Here, we develop a two‐step double‐solvent strategy to grow and confine CsPbBr3 QDs within the three‐dimensional (3D) cavities of a mesoporous SBA‐16 silica scaffold (CsPbBr3@SBA‐16). Strong confinement and separation of the MHP QDs lead to a relatively uniform size distribution, narrow luminescence, and good ambient stability over 2 months. In addition, the CsPbBr3@SBA‐16 presents a high activity and stability for visible‐light‐driven photocatalytic toluene C(sp3)–H bond activation to produce benzaldehyde with ∼730 µmol g−1 h−1 yield rate and near‐unity selectivity. Similarly, the structural stability of CsPbBr3@SBA‐16 QDs is superior to that of both pure CsPbBr3 QDs and those confined in MCM‐41 with 1D channels. [ABSTRACT FROM AUTHOR]

Published
2024
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10. Electrochemical reduction of nitrate to hydroxylamine on gold electrode.

Author

Xie, Yangshan, De Ras, Michiel, Zhao, Jiwu, Liu, Tianxi, Lai, Feili, Hofkens, Johan, and Roeffaers, Maarten B. J.

Subjects
DENITRIFICATION, GOLD electrodes, HYDROXYLAMINE, GOLD, NITRATES
Abstract

In this study, we explore the efficacy of gold (Au) as a selective electrocatalyst for the reduction of nitrate to hydroxylamine, a valuable nitrogen-based chemical, while also evaluating the by-product formation of ammonia. We systematically optimized various experimental parameters including nitrate concentration, pH, and applied potential. We found that at an applied potential of −0.7 V vs. RHE in 0.1 M HNO3, Au achieves a 230.1 ± 19 μmol NH2OH h−1 cm−2 yield, with a 34.2 ± 2.8% faradaic efficiency. This study underscores the potential of Au as an efficient and selective electrocatalyst for generating value-added nitrogen products through an electrochemical pathway. [ABSTRACT FROM AUTHOR]

Published
2024
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12. Two-dimensional perovskites with alternating cations in the interlayer space for stable light-emitting diodes

Author

Zhang Yiyue, Keshavarz Masoumeh, Debroye Elke, Fron Eduard, Rodríguez González Miriam Candelaria, Naumenko Denys, Amenitsch Heinz, Van de Vondel Joris, De Feyter Steven, Heremans Paul, Roeffaers Maarten B. J., Qiu Weiming, Pradhan Bapi, and Hofkens Johan

Subjects
alternating interlayer cations, light-emitting diodes, stability, two-dimensional perovskites, Physics, QC1-999
Abstract

Lead halide perovskites have attracted tremendous attention in photovoltaics due to their impressive optoelectronic properties. However, the poor stability of perovskite-based devices remains a bottleneck for further commercial development. Two-dimensional perovskites have great potential in optoelectronic devices, as they are much more stable than their three-dimensional counterparts and rapidly catching up in performance. Herein, we demonstrate high-quality two-dimensional novel perovskite thin films with alternating cations in the interlayer space. This innovative perovskite provides highly stable semiconductor thin films for efficient near-infrared light-emitting diodes (LEDs). Highly efficient LEDs with tunable emission wavelengths from 680 to 770 nm along with excellent operational stability are demonstrated by varying the thickness of the interlayer spacer cation. Furthermore, the best-performing device exhibits an external quantum efficiency of 3.4% at a high current density (J) of 249 mA/cm2 and remains above 2.5% for a J up to 720 mA cm−2, leading to a high radiance of 77.5 W/Sr m2 when driven at 6 V. The same device also shows impressive operational stability, retaining almost 80% of its initial performance after operating at 20 mA/cm2 for 350 min. This work provides fundamental evidence that this novel alternating interlayer cation 2D perovskite can be a promising and stable photonic emitter.

Published
2021
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16. Noble‐Metal‐Free High‐Entropy Alloy Nanoparticles for Efficient Solar‐Driven Photocatalytic CO2 Reduction

Author

Huang, Haowei, primary, Zhao, Jiwu, additional, Guo, Hele, additional, Weng, Bo, additional, Zhang, Hongwen, additional, Saha, Rafikul Ali, additional, Zhang, Menglong, additional, Lai, Feili, additional, Zhou, Yufan, additional, Juan, Rubio‐Zuazo, additional, Chen, Peng‐Cheng, additional, Wang, Sibo, additional, Steele, Julian A., additional, Zhong, Fulan, additional, Liu, Tianxi, additional, Hofkens, Johan, additional, Zheng, Yu‐Ming, additional, Long, Jinlin, additional, and Roeffaers, Maarten B. J., additional

Published
2024
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17. Thermal unequilibrium of strained black CsPbI₃ thin films

Author

Steele, Julian A., Jin, Handong, Dovgaliuk, Iurii, Berger, Robert F., Braeckevelt, Tom, Yuan, Haifeng, Martin, Cristina, Solano, Eduardo, Lejaeghere, Kurt, Rogge, Sven M. J., Notebaert, Charlotte, Vandezande, Wouter, Janssen, Kris P. F., Goderis, Bart, Debroye, Elke, Wang, Ya-Kun, Dong, Yitong, Ma, Dongxin, Saidaminov, Makhsud, Tan, Hairen, Lu, Zhenghong, Dyadkin, Vadim, Chernyshov, Dmitry, Van Speybroeck, Veronique, Sargent, Edward H., Hofkens, Johan, and Roeffaers, Maarten B. J.

Published
2019

18. Manipulating crystallization dynamics through chelating molecules for bright perovskite emitters

Author

Zou, Yatao, Teng, Pengpeng, Xu, Weidong, Zheng, Guanhaojie, Lin, Weihua, Yin, Jun, Kobera, Libor, Abbrent, Sabina, Li, Xiangchun, Steele, Julian A., Solano, Eduardo, Roeffaers, Maarten B. J., Li, Jun, Cai, Lei, Kuang, Chaoyang, Scheblykin, Ivan G., Brus, Jiri, Zheng, Kaibo, Yang, Ying, Mohammed, Omar F., Bakr, Osman M., Pullerits, Tönu, Bai, Sai, Sun, Baoquan, and Gao, Feng

Published
2021
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21. In Situ Annealing Effect on Thermally Co-Evaporated CsPbI2Br Thin Films Studied via Spectroscopic Ellipsometry

Author

Papadopoulou, Athina, Saha, Rafikul Ali, Pintor-Monroy, Maria Isabel, Song, Wenya, Lieberman, Itai, Solano, Eduardo, Roeffaers, Maarten B. J., Gehlhaar, Robert, and Genoe, Jan

Abstract

All-inorganic cesium lead halide perovskites possess excellent thermal stability, a feature that renders them highly favorable for optoelectronic applications with an elevated thermal budget. Employing a coevaporation approach for their deposition holds promise for manufacturing at an industrial level, owing to improvements in device scalability and reproducibility. For unlocking the full potential of vacuum-evaporated perovskite thin films, it is crucial to delve deeper into their crystallization process, which, as a solid-state reaction, has been less investigated compared to the crystallization process of, most commonly used, solution-based methods. In this work, we employ spectroscopic ellipsometry, a nondestructive, high speed, and high accuracy characterization method, to study the real time annealing effect on thermally coevaporated CsPbI2Br thin films in a temperature range between 25 and 300 °C. We achieve this by developing a singular dynamic model that can be fitted in real time as a function of temperature, providing insights into how thermal annealing influences the perovskite film’s morphology and optical constants. Based on the latter, we derive the temperature dependence of the thermo-optic coefficient and Urbach energy as well as analyze the interband transition energies via critical point analysis. We demonstrate that the γ- to β-phase transition can be identified through a pronounced shift in the bandgap energy, whereas the β- to α-phase transition can be discerned by a sharp increase in the film’s roughness. We corroborate the obtained fit results with additional in- and ex situ measurements, such as in situ grazing incidence wide-angle X-ray scattering, atomic force microscopy, reflectance/transmittance, and profilometry.

Published
2024
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22. Investigation of the Octahedral Network Structure in Formamidinium Lead Bromide Nanocrystals by Low-Dose Scanning Transmission Electron Microscopy

Author

Schrenker, Nadine J., Braeckevelt, Tom, De Backer, Annick, Livakas, Nikolaos, Yu, Chu-Ping, Friedrich, Thomas, Roeffaers, Maarten B. J., Hofkens, Johan, Verbeeck, Johan, Manna, Liberato, Van Speybroeck, Veronique, Van Aert, Sandra, and Bals, Sara

Abstract

Metal halide perovskites (MHP) are highly promising semiconductors. In this study, we focus on FAPbBr3nanocrystals, which are of great interest for green light-emitting diodes. Structural parameters significantly impact the properties of MHPs and are linked to phase instability, which hampers long-term applications. Clearly, there is a need for local and precise characterization techniques at the atomic scale, such as transmission electron microscopy. Because of the high electron beam sensitivity of MHPs, these investigations are extremely challenging. Here, we applied a low-dose method based on four-dimensional scanning transmission electron microscopy. We quantified the observed elongation of the projections of the Br atomic columns, suggesting an alternation in the position of the Br atoms perpendicular to the Pb–Br–Pb bonds. Together with molecular dynamics simulations, these results remarkably reveal local distortions in an on-average cubic structure. Additionally, this study provides an approach to prospectively investigating the fundamental degradation mechanisms of MHPs.

Published
2024
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26. Oxygen-Mediated (0D) Cs4PbX6 Formation during Open-Air Thermal Processing Improves Inorganic Perovskite Solar Cell Performance.

Author

Saha, Rafikul Ali, Chiu, Wei-Hsun, Degutis, Giedrius, Chen, Peng, Filez, Matthias, Solano, Eduardo, Orlov, Nikolai, De Angelis, Francesco, Ariza, Rocío, Meneghini, Carlo, Detavernier, Christophe, Mali, Sawanta S., Hoang, Minh Tam, Yang, Yang, Garnett, Erik C., Wang, Lianzhou, Wang, Hongxia, Roeffaers, Maarten B. J., and Steele, Julian A.

Published
2024
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29. Additivity of Atomic Strain Fields as a Tool to Strain-Engineering Phase-Stabilized CsPbI3 Perovskites

Author

Teunissen, Johannes L., primary, Braeckevelt, Tom, additional, Skvortsova, Irina, additional, Guo, Jinhui, additional, Pradhan, Bapi, additional, Debroye, Elke, additional, Roeffaers, Maarten B. J., additional, Hofkens, Johan, additional, Van Aert, Sandra, additional, Bals, Sara, additional, Rogge, Sven M. J., additional, and Van Speybroeck, Veronique, additional

Published
2023
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30. Nanoscale Chemical Diversity of Coke Deposits on Nano‐Printed Metal Catalysts Visualized by Tip‐Enhanced Raman Spectroscopy

Author

Filez, Matthias, primary, Walke, Peter, additional, Le‐The, Hai, additional, Toyouchi, Shuichi, additional, Peeters, Wannes, additional, Tomkins, Patrick, additional, Eijkel, Jan C. T., additional, De Feyter, Steven, additional, Detavernier, Christophe, additional, De Vos, Dirk E., additional, Uji‐I, Hiroshi, additional, and Roeffaers, Maarten B. J., additional

Published
2023
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31. Cation Substitution Strategy for Developing Perovskite Oxide with Rich Oxygen Vacancy-Mediated Charge Redistribution Enables Highly Efficient Nitrate Electroreduction to Ammonia

Author

Chu, Kaibin, primary, Zong, Wei, additional, Xue, Guohao, additional, Guo, Hele, additional, Qin, Jingjing, additional, Zhu, Haiyan, additional, Zhang, Nan, additional, Tian, Zhihong, additional, Dong, Hongliang, additional, Miao, Yue-E., additional, Roeffaers, Maarten B. J., additional, Hofkens, Johan, additional, Lai, Feili, additional, and Liu, Tianxi, additional

Published
2023
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33. Oxygen-Mediated (0D) Cs4PbX6Formation during Open-Air Thermal Processing Improves Inorganic Perovskite Solar Cell Performance

Author

Saha, Rafikul Ali, Chiu, Wei-Hsun, Degutis, Giedrius, Chen, Peng, Filez, Matthias, Solano, Eduardo, Orlov, Nikolai, De Angelis, Francesco, Ariza, Rocío, Meneghini, Carlo, Detavernier, Christophe, Mali, Sawanta S., Hoang, Minh Tam, Yang, Yang, Garnett, Erik C., Wang, Lianzhou, Wang, Hongxia, Roeffaers, Maarten B. J., and Steele, Julian A.

Abstract

The desire to commercialize perovskite solar cells continues to mount, motivating the development of scalable production. Evaluations of the impact of open-air processing have revealed a variety of physical changes in the fabricated devices─with few changes having the capacity to be functionalized. Here, we highlight the beneficial role of ambient oxygen during the open-air thermal processing of metastable γ-CsPbI3-based perovskite thin films and devices. Physiochemical-sensitive probes elucidate oxygen intercalation and the formation of Pb–O bonds in the CsPbI3crystal, entering via iodine vacancies at the surface, creating superoxide (O2–) through electron transfer reactions with molecular oxygen, which drives the formation of a zero-dimensional Cs4PbI6capping layer during annealing (>330 °C). The chemical conversion permanently alters the film structure, helping to shield the subsurface perovskite from moisture and introduces lattice anchoring sites, stabilizing otherwise unstable γ-CsPbI3films. This functional modification is demonstrated in γ-CsPbI2Br perovskite solar cells, boosting the operational stability and photoconversion efficiency of champion devices from 12.7 to 15.4% when annealed in dry air. Such findings prompt a reconsideration of glovebox-based perovskite solar cell research and establish a scenario where device fabrication can in fact greatly benefit from ambient oxygen.

Published
2024
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34. Tailoring bismuth defects in Bi2WO6 nanosheets for photocatalytic C–H activation.

Author

Li, Xinye, Luo, Luteng, Guo, Hele, Weng, Bo, Sun, Li, Velpula, Gangamallaiah, Aslam, Imran, Roeffaers, Maarten B. J., Chen, Qinghua, Zeng, Lingxing, Yang, Min-Quan, and Qian, Qingrong

Abstract

Functionalizing sp3 C–H bonds in toluene through photocatalysis poses a significant challenge in organic synthesis, garnering substantial research attention. Nevertheless, the inert nature of the C–H bond restricts the photocatalytic conversion efficiency. Here, we construct bismuth defect modified ultrathin Bi2WO6 nanosheets (BT-48) for the conversion of toluene into benzaldehyde under light irradiation. Density functional theory (DFT) calculations validate the effectiveness of Bi defects in Bi2WO6 in activating the C–H bond in toluene. Moreover, a comprehensive physiochemical analysis shows that the introduction of bismuth defects in ultrathin Bi2WO6 nanosheets could promote the separation of photoexcited charge carriers. As a result, the optimal BT-48 sample exhibits an impressive benzaldehyde formation (6781 μmol g−1 h−1) with a high selectivity of 96%, which is 6 times higher than that of Bi2WO6 (1109 μmol g−1 h−1) and surpasses those of all the previously reported Bi2WO6-based photocatalysts. It is expected that this work could enhance our understanding of designing efficient photocatalysts for the activation of C–H bonds under light illumination. [ABSTRACT FROM AUTHOR]

Published
2024
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35. Placental-fetal distribution of carbon particles in a pregnant rabbit model after repeated exposure to diluted diesel engine exhaust

Author

BONGAERTS, Eva, NAWROT, Tim, WANG, Congrong, AMELOOT, Marcel, BOVE, Hannelore, Roeffaers, Maarten B. J., Chavatte-Palmer, Pascale, Couturier-Tarrade, Anne, Cassee, Flemming R., IRAS OH Toxicology, BONGAERTS, Eva, NAWROT, Tim, WANG, Congrong, AMELOOT, Marcel, BOVE, Hannelore, Roeffaers, Maarten B. J., Chavatte-Palmer, Pascale, Couturier-Tarrade, Anne, and Cassee, Flemming R.

Subjects
ORGANS, Diesel exhaust, Science & Technology, STRESS, GENES, Gestational exposure, Health, Toxicology and Mutagenesis, MATERNAL EXPOSURE, CIRCULATION, Airborne pollution, General Medicine, Toxicology, AMBIENT AIR-POLLUTION, PARTICULATE MATTER PM2.5, NUTRITION, WEIGHT, GESTATION, Life Sciences & Biomedicine, Label-free detection
Abstract

BackgroundAirborne pollution particles have been shown to translocate from the mother's lung to the fetal circulation, but their distribution and internal placental-fetal tissue load remain poorly explored. Here, we investigated the placental-fetal load and distribution of diesel engine exhaust particles during gestation under controlled exposure conditions using a pregnant rabbit model. Pregnant dams were exposed by nose-only inhalation to either clean air (controls) or diluted and filtered diesel engine exhaust (1 mg/m(3)) for 2 h/day, 5 days/week, from gestational day (GD) 3 to GD27. At GD28, placental and fetal tissues (i.e., heart, kidney, liver, lung and gonads) were collected for biometry and to study the presence of carbon particles (CPs) using white light generation by carbonaceous particles under femtosecond pulsed laser illumination.ResultsCPs were detected in the placenta, fetal heart, kidney, liver, lung and gonads in significantly higher amounts in exposed rabbits compared with controls. Through multiple factor analysis, we were able to discriminate the diesel engine exposed pregnant rabbits from the control group taking all variables related to fetoplacental biometry and CP load into consideration. Our findings did not reveal a sex effect, yet a potential interaction effect might be present between exposure and fetal sex.ConclusionsThe results confirmed the translocation of maternally inhaled CPs from diesel engine exhaust to the placenta which could be detected in fetal organs during late-stage pregnancy. The exposed can be clearly discriminated from the control group with respect to fetoplacental biometry and CP load. The differential particle load in the fetal organs may contribute to the effects on fetoplacental biometry and to the malprogramming of the fetal phenotype with long-term effects later in life. The detection equipment was funded by the METHUSALEM Program and the INCALO project (ERC-PoC). The authors acknowledge the Flemish Scientific Research Foundation (FWO; 1150920 N to E.B. and G082317N). Animal exposure and sample collection was supported by ANR grant ANR-13-CESA0011-EPAPP (P.C.P.) and by ERC consolidator grant N°311765–E-DOHaD (PI, R. Slama). The authors thank the Advanced Optical Microscopy Centre (Hasselt University) for their assistance and maintenance of the microscopic instruments. We also thank SAAJ from INRAE (Livestock PhysiologyReproduction and Animal Diets Experimental Facility, https://doi. org/10.17180/MAQZ-V844).

Published
2023

36. How to GIWAXS: Grazing Incidence Wide Angle X‐Ray Scattering Applied to Metal Halide Perovskite Thin Films

Author

Steele, Julian A., primary, Solano, Eduardo, additional, Hardy, David, additional, Dayton, Damara, additional, Ladd, Dylan, additional, White, Keith, additional, Chen, Peng, additional, Hou, Jingwei, additional, Huang, Haowei, additional, Saha, Rafikul Ali, additional, Wang, Lianzhou, additional, Gao, Feng, additional, Hofkens, Johan, additional, Roeffaers, Maarten B. J., additional, Chernyshov, Dmitry, additional, and Toney, Michael F., additional

Published
2023
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38. Edge stabilization in reduced-dimensional perovskites

Author

Na Quan, Li, Ma, Dongxin, Zhao, Yongbiao, Voznyy, Oleksandr, Yuan, Haifeng, Bladt, Eva, Pan, Jun, García de Arquer, F. Pelayo, Sabatini, Randy, Piontkowski, Zachary, Emwas, Abdul-Hamid, Todorović, Petar, Quintero-Bermudez, Rafael, Walters, Grant, Fan, James Z., Liu, Mengxia, Tan, Hairen, Saidaminov, Makhsud I., Gao, Liang, Li, Yiying, Anjum, Dalaver H., Wei, Nini, Tang, Jiang, McCamant, David W., Roeffaers, Maarten B. J., Bals, Sara, Hofkens, Johan, Bakr, Osman M., Lu, Zheng-Hong, and Sargent, Edward H.

Published
2020
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41. How to GIWAXS: Grazing Incidence Wide Angle X-Ray Scattering Applied to Metal Halide Perovskite Thin Films

Author

Steele, Julian A., Solano, Eduardo, Hardy, David, Dayton, Damara, Ladd, Dylan, White, Keith, Chen, Peng, Hou, Jingwei, Huang, Haowei, Saha, Rafikul Ali, Wang, Lianzhou, Gao, Feng, Hofkens, Johan, Roeffaers, Maarten B. J., Chernyshov, Dmitry, Toney, Michael F., Steele, Julian A., Solano, Eduardo, Hardy, David, Dayton, Damara, Ladd, Dylan, White, Keith, Chen, Peng, Hou, Jingwei, Huang, Haowei, Saha, Rafikul Ali, Wang, Lianzhou, Gao, Feng, Hofkens, Johan, Roeffaers, Maarten B. J., Chernyshov, Dmitry, and Toney, Michael F.

Abstract

The frequency of reports utilizing synchrotron-based grazing incident wide angle X-ray scattering (GIWAXS) to study metal halide perovskite thin films has exploded recently, as this technique has proven invaluable for understanding several structure-property relationships that fundamentally limit optoelectronic performance. The GIWAXS geometry and temporal resolution are also inherently compatible with in situ and operando setups (including ISOS protocols), and a relatively large halide perovskite research community has deployed GIWAXS to unravel important kinetic and dynamic features in these materials. Considering its rising popularity, the aim here is to accelerate the required learning curve for new experimentalists by clearly detailing the underlying analytical concepts which can be leveraged to maximize GIWAXS studies of polycrystalline thin films and devices. Motivated by the vast range of measurement conditions offered, together with the wide variety of compositions and structural motifs available (i.e., from single-crystal and polycrystalline systems, to quantum dots and layered superlatices), a comprehensive framework for conducting effective GIWAXS experiments is outlined for different purposes. It is anticipated that providing a clear perspective for this topic will help elevate the quality of future GIWAXS studies-which have become routine-and provide the impetus required to develop novel GIWAXS approaches to resolve unsettled scientific questions., Funding Agencies|Research Foundation - Flanders [FWO] [1242922N, 12Y7221N, V400622N]; FWO through research projects [G098319N, G0A5923N, S002019N, S004322N, ZW15_09-GOH6316]; KU Leuven Research fund [Meth/15/04]; Flemish government [CASAS2]; KU Leuven Industrial Research Fund [C3/19/046]; U.S. Department of Energy (DOE) Solar Energy Technology Office (SETO) of Energy Efficiency and Renewable Energy (EERE) award; Australian Research Council [FL190100139, DP230100621, FT210100589, DP230101901, DE230101712, DE230100173]; Centre for Microscopy and Microanalysis (CMM); Australian National Fabrication Facility (ANFF), University of Queensland; University of Queenslands Knowledge Exchange and Translation Fund Award; Swedish Energy Agency [46564-1]; [iBOF-21-085]

Published
2023
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42. Tethered Small-Molecule Acceptors Simultaneously Enhance the Efficiency and Stability of Polymer Solar Cells

Author

Li, Shangyu, Zhang, Rui, Zhang, Ming, Yao, Jia, Peng, Zhengxing, Chen, Qi, Zhang, Cen, Chang, Bowen, Bai, Yang, Fu, Hongyuan, Ouyang, Yanni, Zhang, Chunfeng, Steele, Julian A., Alshahrani, Thamraa, Roeffaers, Maarten B. J., Solano, Eduardo, Meng, Lei, Gao, Feng, Li, Yongfang, Zhang, Zhi-Guo, Li, Shangyu, Zhang, Rui, Zhang, Ming, Yao, Jia, Peng, Zhengxing, Chen, Qi, Zhang, Cen, Chang, Bowen, Bai, Yang, Fu, Hongyuan, Ouyang, Yanni, Zhang, Chunfeng, Steele, Julian A., Alshahrani, Thamraa, Roeffaers, Maarten B. J., Solano, Eduardo, Meng, Lei, Gao, Feng, Li, Yongfang, and Zhang, Zhi-Guo

Abstract

For polymer solar cells (PSCs), the mixture of polymer donors and small-molecule acceptors (SMAs) is fine-tuned to realize a favorable kinetically trapped morphology and thus a commercially viable device efficiency. However, the thermodynamic relaxation of the mixed domains within the blend raises concerns related to the long-term operational stability of the devices, especially in the record-holding Y-series SMAs. Here, a new class of dimeric Y6-based SMAs tethered with differential flexible spacers is reported to regulate their aggregation and relaxation behavior. In their polymer blends with PM6, it is found that they favor an improved structural order relative to that of Y6 counterpart. Most importantly, the tethered SMAs show large glass transition temperatures to suppress the thermodynamic relaxation in mixed domains. For the high-performing dimeric blend, an unprecedented open circuit voltage of 0.87 V is realized with a conversion efficiency of 17.85%, while those of regular Y6-base devices only reach 0.84 V and 16.93%, respectively. Most importantly, the dimer-based device possesses substantially reduced burn-in efficiency loss, retaining more than 80% of the initial efficiency after operating at the maximum power point under continuous illumination for 700 h. The tethering approach provides a new direction to develop PSCs with high efficiency and excellent operating stability., Funding Agencies|National Natural Science Foundation of China [21734008, 22175014]; Fundamental Research Funds for the Central Universities [buctrc201822]; Olle Engkvists Stiftelse [211-0125]; Office of Science, Office of Basic Energy Sciences, of the US Department of Energy [DE-AC02-05CH11231]; Research Foundation - Flanders (FWO) [12Y7221N, V400622N]; KU Leuven Research Fund [C14/19/079, iBOF-21-085 PERSIST]; KU Leuven Industrial Research Fund [C3/19/046]; Princess Nourah bint Abdulrahman University Researchers Supporting project [PNURSP2022R1]

Published
2023
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44. Beyond acceptable limits: intrinsic contamination in commercial 15N2 impedes reliable N2 reduction experiments.

Author

De Ras, Michiel, Hollevoet, Lander, Martens, Johan. A., Liu, Tianxi, Nicolai, Bart M., Hertog, Maarten L. A. T. M., Hofkens, Johan, and Roeffaers, Maarten B. J.

Subjects
NITROGEN
Abstract

The validity of N2 reduction experiments relies on control experiments with isotopically labeled 15N2. Here we discovered significant 15NH3 contamination (73 ppm) in commercial 15N2 and also observed the prescence of oxidized 15N in amounts comparable to the typical reported ammonia yields. [ABSTRACT FROM AUTHOR]

Published
2024
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48. Au–Pd Tandem Photocatalysis for Nonoxidative Coupling of Methane toward Ethylene

Author

Tang, Chengyun, primary, Du, Shulin, additional, Huang, Haowei, additional, Tan, Siyi, additional, Zhao, Jiwu, additional, Zhang, Hongwen, additional, Ni, Wenkang, additional, Yue, Xuanyu, additional, Ding, Zhengxin, additional, Zhang, Zizhong, additional, Yuan, Rusheng, additional, Dai, Wenxin, additional, Fu, Xianzhi, additional, Roeffaers, Maarten B. J., additional, and Long, Jinlin, additional

Published
2023
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