Article
Chemistry, Physical
Hyunhwa Lee, Passarut Boonmongkolras, Seongmoon Jun, Daehan Kim, Yujin Park, Jaehyuk Koh, Yong-Hoon Cho, Byungha Shin, Jeong Young Park
Summary: Mixed-halide perovskites show tunable optical properties and have potential applications in optoelectronics, but the phase segregation caused by halide ion migration hinders stable performance in solar cells. By conducting comprehensive measurements, we have revealed the mechanism of ion migration and observed that iodide ions predominantly cause halide segregation. The changes in band bending at grain boundaries indicate the migration of iodide ions towards grain boundaries and their influence on the formation of iodine-rich phases. This study provides insights into the mechanism of light-halide ion interactions.
ACS APPLIED ENERGY MATERIALS
(2023)
Review
Materials Science, Multidisciplinary
Ming Yang, Huaxin Wang, Wensi Cai, Zhigang Zang
Summary: Recently, mixed-halide inorganic CsPbI3-xBrx perovskite solar cells (PSCs) have shown significant advancements, offering balanced efficiency, stability, tunable bandgap, and potential for indoor photovoltaic applications. However, challenges such as phase segregation, trap state density, and absorption range limitations still need to be addressed. This review provides an analysis of the crystal and electronic structure of CsPbI3-xBrx, explores potential solutions for phase segregation inhibition and interface engineering, and highlights the crucial role of interface modification in the performance of CsPbI3-xBrx PSCs. Furthermore, it discusses the suitability of CsPbI3-xBrx PSCs for indoor photovoltaics due to their adjustable bandgap and notable strength stability.
ADVANCED OPTICAL MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Junsang Cho, Preethi S. Mathew, Jeffrey T. DuBose, Prashant Kamat
Summary: 2D lead halide perovskites with tunable bandgap and enhanced chemical stability are useful for designing optoelectronic devices. Reducing dimensionality can increase resistance to light-induced ion migration, but also decreases the efficiency of halide ion segregation and segregation rate constant, leading to a decrease in charge-carrier lifetime.
ADVANCED MATERIALS
(2021)
Article
Chemistry, Multidisciplinary
Shengnan Feng, Yu Ju, Rentong Duan, Zaiqin Man, Shuyi Li, Fengrui Hu, Chunfeng Zhang, Shuxia Tao, Weihua Zhang, Min Xiao, Xiaoyong Wang
Summary: Periodic heating of CsPbBr1.2I1.8 nanocrystals can completely suppress the phase-segregation effect under strong light illumination.
ADVANCED MATERIALS
(2023)
Article
Nanoscience & Nanotechnology
Wenming Chai, Junxiao Ma, Weidong Zhu, Dazheng Chen, He Xi, Jincheng Zhang, Chunfu Zhang, Yue Hao
Summary: All-inorganic perovskite CsPbIBr2 materials show promise for optoelectronics, but tend to undergo halide phase segregation under illumination, impacting their properties. By modifying the crystalline grains with PMMA, researchers successfully overcame this issue, resulting in improved performance of CsPbIBr2 films.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Chemistry, Physical
Fan Xu, Meng Zhang, Zikun Li, Xiaoyu Yang, Rui Zhu
Summary: Wide-bandgap (WBG) perovskite solar cells (PSCs) are promising candidates for multijunction tandem and building photovoltaics, but their performance still lags behind pure-iodide counterparts due to complex compositional evolution, significant photovoltage deficits, and intrinsic spectral losses. This article comprehensively discusses the drawbacks of WBG PSCs from a device perspective and proposes three critical issues for growing high-quality WBG perovskites. The prospects for future advancements and commercialization of WBG PSCs are also presented to guide upcoming research hotspots.
ADVANCED ENERGY MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Ya-Kun Wang, Kamalpreet Singh, Jiao-Yang Li, Yitong Dong, Xue-Qi Wang, Joao M. Pina, You-Jun Yu, Randy Sabatini, Yang Liu, Dongxin Ma, Jun Liu, Zeke Liu, Yiyuan Gao, Oleksandr Voznyy, Wanli Ma, Man-Keung Fung, Liang-Sheng Liao, Edward H. Sargent
Summary: The issue of instability in mixed-halide perovskites (MHPs) has been addressed by introducing inorganic ligands, resulting in improved colloidal and photo-stability. The new materials exhibit high efficiency and narrow emission spectrum in light-emitting diodes (LEDs), with enhanced operating stability.
ADVANCED MATERIALS
(2022)
Article
Chemistry, Multidisciplinary
Zhaojian Xu, Ross A. Kerner, Joseph J. Berry, Barry P. Rand
Summary: Due to their straightforward stoichiometry-bandgap tunability, mixed-halide perovskites are ideal for many optoelectronic devices. However, unwanted halide segregation under operational conditions restricts practical use, and the origin of voltage-induced halide segregation is still unclear.
ADVANCED FUNCTIONAL MATERIALS
(2022)
Article
Materials Science, Multidisciplinary
Zhenni Lin, Ye Zhang, Mengyu Gao, Julian A. Steele, Sheena Louisia, Sunmoon Yu, Li Na Quan, Chung-Kuan Lin, David T. Limmer, Peidong Yang
Summary: Experimental evidence shows that the phase transformation of cesium lead iodide under controlled relative humidity is nucleation limited, with higher humidity leading to a lower nucleation barrier. Heating between 40 degrees C and 80 degrees C facilitates water desorption and suppresses phase transformation.
Article
Chemistry, Multidisciplinary
Weichuang Yang, Hanlin Long, Xuan Sha, Jingsong Sun, Yunxing Zhao, Chenyu Guo, Xianchun Peng, Chunhui Shou, Xi Yang, Jiang Sheng, Zhenhai Yang, Baojie Yan, Jichun Ye
Summary: This study clarifies the correlation between phase segregation and voltage losses in wide bandgap mixed-halide perovskite solar cells (PSCs) through experiments and simulations. It is confirmed that suppressing phase segregation can increase the open-circuit voltage (V-oc) and improve device performance. Electrical simulation reveals that performance degradation is attributed to bulk recombination caused by energy level mismatch. The study provides guidance for the development of high-performance mixed-halide PSCs.
ADVANCED FUNCTIONAL MATERIALS
(2022)
Article
Chemistry, Physical
Junshuai Zhang, Jialong Duan, Qiyao Guo, Qiaoyu Zhang, Yuanyuan Zhao, Hao Huang, Yanyan Duan, Qunwei Tang
Summary: Researchers have developed a method to suppress halide segregation by constructing conjugated covalent organic frameworks. This method effectively solidifies the material structure, slows down the light-induced segregation process, and improves the efficiency and stability of solar cells.
ACS ENERGY LETTERS
(2022)
Review
Chemistry, Multidisciplinary
Rui He, Shengqiang Ren, Cong Chen, Zongjin Yi, Yi Luo, Huagui Lai, Wenwu Wang, Guanggen Zeng, Xia Hao, Ye Wang, Jingquan Zhang, Changlei Wang, Lili Wu, Fan Fu, Dewei Zhao
Summary: The past decade has seen significant advancements in perovskite solar cells, particularly in the role of wide-bandgap PSCs in tandem solar cells. Current efforts are focused on addressing stability and efficiency issues in both organic-inorganic hybrid perovskites and all-inorganic perovskites.
ENERGY & ENVIRONMENTAL SCIENCE
(2021)
Article
Energy & Fuels
Xinbo Chu, Qiufeng Ye, Zhenhan Wang, Chen Zhang, Fei Ma, Zihan Qu, Yang Zhao, Zhigang Yin, Hui-Xiong Deng, Xingwang Zhang, Jingbi You
Summary: In this study, the surface of inorganic perovskite was treated with caesium fluoride, resulting in a wider-bandgap perovskite. This treatment improved carrier lifetime and hole extraction efficiency, providing an effective approach for the design of efficient solar cells.
Article
Chemistry, Physical
Zhuoxin Li, Xing Li, Xianggang Chen, Xiaoxia Cui, Chunlin Guo, Xuzheng Feng, Dongxu Ren, Yaqi Mo, Miao Yang, Huiwei Huang, Rui Jia, Xuepeng Liu, Liyuan Han, Songyuan Dai, Molang Cai
Summary: A highly crystalline blocking structure was assembled onto wide band gap mixed-halide perovskite solar cells to improve device performance and stability. This structure contributed to the release of lattice strain, enhancement of halide-ion migration barrier, and effective defect passivation, resulting in impressive open-circuit voltage and efficiency.
Article
Chemistry, Multidisciplinary
Mehri Ghasemi, Xuemei Li, Cheng Tang, Qi Li, Junlin Lu, Aijun Du, Jaeho Lee, Dominique Appadoo, Luiz H. G. Tizei, Sang T. Pham, Lianzhou Wang, Sean M. Collins, Jingwei Hou, Baohua Jia, Xiaoming Wen
Summary: This research explores the creation of stable nanocomposites by embedding mixed-halide perovskites in a glassy metal-organic framework. The study identifies a direct relationship between the halide composition and emission energy at the nanoscale and reveals that interfacial binding is the key factor in inhibiting phase segregation.
Article
Nanoscience & Nanotechnology
Yuhang Zhao, Radwan M. Sarhan, Alberto Eljarrat, Zdravko Kochovski, Christoph Koch, Bernd Schmidt, Wouter Koopman, Yan Lu
Summary: Bimetallic nanostructures can generate a new type of photo-enhanced nanoreactors by utilizing photo-generated heat to accelerate catalytic reactions. The study demonstrates that the photothermal conversion of Au-Pd nanorods can be improved by coating with polydopamine or TiO2, resulting in increased reaction rates.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Chemistry, Multidisciplinary
Denis Yagodkin, Kyrylo Greben, Alberto Eljarrat Ascunce, Sviatoslav Kovalchuk, Mahdi Ghorbani-Asl, Mitisha Jain, Silvan Kretschmer, Nikolai Severin, Juergen P. Rabe, Arkady Krasheninnikov, Christoph T. Koch, Kirill Bolotin
Summary: A new localized excitonic state is demonstrated in patterned monolayer 2D semiconductors. The state is distinguished by non-linear power dependence and can survive up to room temperature. It is shown to be of extrinsic origin, likely associated with charge transfer excitons from the organic substance deposited onto the 2D semiconductor.
ADVANCED FUNCTIONAL MATERIALS
(2022)
Article
Chemistry, Multidisciplinary
Klara Suchan, Justus Just, Pascal Beblo, Carolin Rehermann, Aboma Merdasa, Roland Mainz, Ivan G. Scheblykin, Eva Unger
Summary: This study investigates the effect of compositional range on light-induced phase-segregation phenomena in methylammonium lead bromide/iodide samples using simultaneous in situ XRD and PL measurements. The results suggest that the initial stage of photo-segregation can be rationalized by thermodynamic models, but the progression of phase segregation is also influenced by long-lived accumulative photo-induced material alterations. Additional photo-induced defects, such as halide vacancies and interstitials, should be considered to fully understand the mechanism of light-induced phase segregation.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Kate Reidy, Paulina Ewa Majchrzak, Benedikt Haas, Joachim Dahl Thomsen, Andrea Konecna, Eugene Park, Julian Klein, Alfred J. H. Jones, Klara Volckaert, Deepnarayan Biswas, Matthew D. Watson, Cephise Cacho, Prineha Narang, Christoph T. Koch, Soren Ulstrup, Frances M. Ross, Juan Carlos Idrobo
Summary: The integration of metallic contacts with 2D semiconductors can significantly affect the local optoelectronic properties. In this study, we analyze the local excitonic changes in a 2D semiconductor MoS2 in contact with Au. Our findings suggest that the observed changes are due to the dielectric screening of the excitonic Coulomb interaction, and increasing the van der Waals distance can optimize excitonic spectra in mixed-dimensional interfaces.
Review
Chemistry, Physical
Osbel Almora, Derya Baran, Guillermo C. Bazan, Carlos I. Cabrera, Sule Erten-Ela, Karen Forberich, Fei Guo, Jens Hauch, Anita W. Y. Ho-Baillie, T. Jesper Jacobsson, Rene A. J. Janssen, Thomas Kirchartz, Nikos Kopidakis, Maria A. Loi, Richard R. Lunt, Xavier Mathew, Michael D. McGehee, Jie Min, David B. Mitzi, Mohammad K. Nazeeruddin, Jenny Nelson, Ana F. Nogueira, Ulrich W. Paetzold, Barry P. Rand, Uwe Rau, Henry J. Snaith, Eva Unger, Lidice Vaillant-Roca, Chenchen Yang, Hin-Lap Yip, Christoph J. Brabec
Summary: This article summarizes the best achievements in the performance of emerging photovoltaic devices in various research subjects, as reported in peer-reviewed articles since August 2021. The article provides updated graphs, tables, and analyses of performance parameters, and compares them based on the photovoltaic bandgap energy and average visible transmittance. The scope of the report is expanded to include triple junction solar cells.
ADVANCED ENERGY MATERIALS
(2023)
Article
Nanoscience & Nanotechnology
Thorsten Schultz, Max Kneiss, Philipp Storm, Daniel Splith, Holger von Wenckstern, Christoph T. Koch, Adnan Hammud, Marius Grundmann, Norbert Koch
Summary: In this study, it is found through simulations that the detection wavelength range of GaAs/AlxGa1-xAs quantum well infrared photodetectors (QWIPs), which are currently state-of-the-art, can be substantially improved using kappa-([Al,In](x)Ga1-x)(2)O-3, while being transparent to visible light and insensitive to photon noise due to its wide band gap. It is also demonstrated that the efficiency of QWIPs critically depends on the quantum well thickness, making precise control and determination of the thickness essential.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Physics, Applied
Daniel Abou-Ras, Ulrike Bloeck, Sebastian Caicedo-Davila, Alberto Eljarrat, Hannah Funk, Adnan Hammud, Sinju Thomas, Dan R. Wargulski, Thomas Lunkenbein, Christoph T. Koch
Summary: This passage presents a practical tutorial on the application of correlative microscopy in optoelectronic semiconductor materials and devices. It discusses the combination of electron microscopy, scanning probe microscopy, and light microscopy for analyzing material and device properties. The tutorial also covers specimen preparation and demonstrates the ability of electron microscopy to monitor phase segregation processes in semiconductor nanoparticles and thin films, along with the explanation of algorithms for extracting phase information.
JOURNAL OF APPLIED PHYSICS
(2023)
Article
Chemistry, Multidisciplinary
Benedikt Haas, Tara M. Boland, Christian Elsaesser, Arunima K. Singh, Katia March, Juri Barthel, Christoph T. Koch, Peter Rez
Summary: Phonon scattering at grain boundaries plays a crucial role in controlling the thermal conductivity of nanoscale devices. This study uses monochromated electron energy loss spectroscopy (EELS) in the scanning transmission electron microscope (STEM) to measure the 60 meV optic mode at grain boundaries in silicon at atomic resolution. The results show the existence of localized phonon modes and support the idea that grain boundaries can act as waveguides.
Article
Microscopy
Christoph T. Koch
Summary: Solving crystal structures from kinematical X-ray or electron diffraction patterns of single crystals requires recording more diffracted beams than the number of atoms in the structure. This method utilizes the fact that multiple scattering encodes structure factor phases in the diffracted intensities to solve the crystallographic phase problem. The retrieval of both amplitudes and phases of electron structure factors from diffraction patterns recorded with varying angle of incidence will be demonstrated, making it potentially useful for electron crystallography of beam-sensitive complex structures.
Article
Chemistry, Physical
Jinzhao Li, Janardan Dagar, Oleksandra Shargaieva, Oliver Maus, Marco Remec, Quiterie Emery, Mark Khenkin, Carolin Ulbrich, Fatima Akhundova, Jose A. Marquez, Thomas Unold, Markus Fenske, Christof Schultz, Bert Stegemann, Amran Al-Ashouri, Steve Albrecht, Alvaro Tejada Esteves, Lars Korte, Hans Koebler, Antonio Abate, Daniel M. Toebbens, Ivo Zizak, Emil J. W. List-Kratochvil, Rutger Schlatmann, Eva Unger
Summary: The authors demonstrate that adjustable ink viscosity can prevent ribbing effects when coating large-area halide perovskite layers. By adding acetonitrile as a co-solvent, smooth and high-quality FAPbI(3) thin-films are obtained. Scaling devices to larger areas, a power conversion efficiency of 17.1% is achieved in laser series-interconnected mini-modules. However, outdoor stability testing shows a decline in performance during warmer summer months.
ADVANCED ENERGY MATERIALS
(2023)
Article
Multidisciplinary Sciences
Marcel Schloz, Johannes Mueller, Thomas C. Pekin, Wouter Van den Broek, Jacob Madsen, Toma Susi, Christoph T. Koch
Summary: We propose a method for reducing the dose required for electron ptychographic reconstruction by adaptively scanning the specimen, providing spatial information redundancy in important regions. The method is based on a deep learning model trained by reinforcement learning using prior knowledge from training data. We demonstrate that adaptive scanning in electron ptychography outperforms alternative low-dose ptychography experiments in terms of reconstruction resolution and quality.
SCIENTIFIC REPORTS
(2023)
Article
Multidisciplinary Sciences
Michael Saliba, Eva Unger, Lioz Etgar, Jingshan Luo, T. Jesper Jacobsson
Summary: In this study, the authors analyze data from the Perovskite Database to investigate the systematic discrepancy between the short circuit current and integrated quantum efficiency in halide perovskites solar cells. This discrepancy persists across various factors, indicating the need for exploring new perovskite physics and updating reporting protocols and assumptions in the field.
NATURE COMMUNICATIONS
(2023)
Article
Chemistry, Multidisciplinary
Vincent R. F. Schroeder, Nicolas Fratzscher, Florian Mathies, Edgar R. Nandayapa, Felix Hermerschmidt, Eva L. Unger, Emil J. W. List-Kratochvil
Summary: We demonstrate the upscaling of inkjet-printed metal halide perovskite light-emitting diodes by optimizing the drying process with an airblade-like slit nozzle. This results in large, continuous perovskite layers in light-emitting diodes with an active area up to 1600 mm(2).
Article
Chemistry, Multidisciplinary
David Burmeister, Alberto Eljarrat, Michele Guerrini, Eva Rock, Julian Plaickner, Christoph T. Koch, Natalie T. Banerji, Caterina Cocchi, Emil J. W. List-Kratochvil, Michael J. Bojdys
Summary: Graphitic carbon nitrides are promising materials for overcoming the limitations of 0D molecular and 1D polymer semiconductors due to their covalently-bonded, layered, and crystalline structure. This study investigates the structural, vibrational, electronic, and transport properties of poly(triazine-imide) (PTI) derivatives with and without intercalated ions. It is found that PTI nano-crystals exhibit high charge carrier density and THz conductivity, but the electroluminescence from the pi-pi* transition is quenched, limiting their use in electroluminescent devices. Macroscopic charge transport in PTI films is also hindered by disorder at crystal-crystal interfaces.
