Article
Chemistry, Physical
Pranjul Bhatt, Amit Kumar, Neha Singh, Ashish Garg, Kanwar Singh Nalwa, Abhishek Tewari
Summary: Partial substitution of CH3NH3 (+) with Cs+ ions has been investigated to suppress iodide vacancy diffusion in MAPI and enhance structural stability. Atomistic simulations and experimental characterization were performed to study the defect chemistry and halide ion mobility in Cs-doped MAPI. The results showed weak dependence of defect clustering and diffusion activation energy on stoichiometry, and confirmed the reduced hysteresis and higher activation energy of halide migration in Cs-doped MAPI.
ACS APPLIED ENERGY MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Chang-Yuan Su, Ye-Feng Yao, Zhi-Xu Zhang, Ying Wang, Ming Chen, Pei-Zhi Huang, Yi Zhang, Wen-Cheng Qiao, Da-Wei Fu
Summary: Two-dimensional hybrid double perovskites have attracted a lot of attention due to their intriguing physical properties. In this study, we successfully synthesized a 2D lead-free ferroelastic material through a structurally progressive strategy. The mechanism of structural phase transition and molecular motion were fully characterized.
Article
Chemistry, Multidisciplinary
Liping Peng, Yulin Xie, Changquan Yang
Summary: This study investigated the photoelectric properties of different metal atoms adsorbed on a 2D perovskite surface, finding that Bi atom adsorption results in the most stable structure, improves charge carrier transfer, and enhances the photoelectric properties significantly compared to Ag and Au adsorption. Additionally, the impact of Bi atom adsorption on 2D perovskite is stronger than that of Ag or Au, as confirmed by light absorption spectrum analysis.
Article
Chemistry, Physical
Rachel Elizabeth Brophy, Movaffaq Kateb, Kristinn Torfason, George Alexandru Nemnes, Halldor Gudfinnur Svavarsson, Ioana Pintilie, Andrei Manolescu
Summary: This study reveals that the diffusion of iodide defects is the most important degradation mechanism in methylammonium lead iodide (MAPI) solar cells, and highlights the influence of internal pressure on the dynamics of these defects. Results show that the diffusion coefficient of an iodide vacancy is one order of magnitude higher than that of interstitial iodide, and this difference increases with increased tensile strain. The diffusion coefficients tend to zero under compressive strain, suggesting that compression of MAPI can effectively reduce its degradation rate. Furthermore, the statistical aspect of deriving the diffusion coefficient using mean squared displacement (MSD) is discussed in terms of initial conditions and simulation time.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Review
Chemistry, Multidisciplinary
Lingmei Kong, Xiaoyu Zhang, Chengxi Zhang, Lin Wang, Sheng Wang, Fan Cao, Dewei Zhao, Andrey L. Rogach, Xuyong Yang
Summary: Metal halide perovskites exhibit excellent electronic and optical properties, making them attractive for low-cost, large-area processing in optoelectronics. However, achieving stability and spectral stability remains a challenge. This review explores the origins of instability in perovskite materials and strategies for improving stability, as well as methods to enhance operational stability in perovskite LEDs.
ADVANCED MATERIALS
(2022)
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
Yongtao Liu, Nikolay Borodinov, Liam Collins, Mahshid Ahmadi, Sergei Kalinin, Olga S. Ovchinnikova, Anton Ievlev
Summary: Ion migration plays a crucial role in metal halide perovskite semiconductor devices, but the mechanisms and effects are not fully understood. Direct observation reveals that decomposition products of CH3NH3+ accumulate at interfaces under light and bias conditions, impacting device performance and stability, highlighting the need for consideration in future optimization studies.
Article
Chemistry, Inorganic & Nuclear
Ze-Jie Wang, Ling-Kun Wu, Na Wang, Qian-Qian Hu, Jian-Rong Li, Heng-Yun Ye
Summary: Organic-inorganic hybrid metal halide perovskites are promising functional materials with excellent photovoltaic performance. However, three-dimensional metal halide perovskites beyond lead halides have been rarely reported. In this study, a new 3D organic-inorganic hybrid ferroelectric material (Me-Hdabco)CsI3 was synthesized and characterized, showing a ferroelectric to paraelectric phase transition and intense photoluminescence with the addition of 10% Sn(ii).
DALTON TRANSACTIONS
(2023)
Article
Chemistry, Physical
Rhys M. Kennard, Clayton J. Dahlman, Ryan A. DeCrescent, Jon A. Schuller, Kunal Mukherjee, Ram Seshadri, Michael L. Chabinyc
Summary: Mechanical strain can modify the structural and electronic properties of methylammonium lead iodide MAPbI(3). The presence of specific twin domains is found to correlate to previously reported strain and defect heterogeneity in MAPbI(3) films. Long-term stability testing reveals that the domain walls are highly immobile over extended periods and nucleation of new domain walls occurs for specific mechanical strains.
CHEMISTRY OF MATERIALS
(2021)
Review
Chemistry, Multidisciplinary
Yinan Jiao, Shenghui Yi, Hanwen Wang, Bing Li, Weizhong Hao, Lulu Pan, Yan Shi, Xiangyu Li, Pengfei Liu, He Zhang, Cunfa Gao, Jinjin Zhao, Jian Lu
Summary: This report summarizes the rapid increase in power conversion efficiencies of solar cells containing metal halide perovskites (MHPs) over the past decade, exceeding 25%. The photovoltaic properties, microstructures, and high-pressure structural evolution of MHPs with anisotropic crystal structures are extensively investigated. The optical/electronic properties of MHPs under thermal, mechanically imposed, and in-service strains/stresses are highlighted, areas that have been previously neglected by researchers.
ADVANCED FUNCTIONAL MATERIALS
(2021)
Article
Chemistry, Multidisciplinary
Hong Wang, Jian-Xin Wang, Xin Song, Tengyue He, Yang Zhou, Osama Shekhah, Luis Gutierrez-Arzaluz, Mehmet Bayindir, Mohamed Eddaoudi, Osman M. Bakr, Omar F. Mohammed
Summary: Lead-free organic metal halide scintillators with low-dimensional electronic structures have shown great potential in X-ray detection and imaging. The organic copper halide CNCI was successfully used to fabricate X-ray scintillators with high sensitivity and resolution. By using a silicon template, the spatial imaging resolution of the CNCI scintillator was further improved.
ACS CENTRAL SCIENCE
(2023)
Article
Chemistry, Multidisciplinary
Bo Zhang, Shuo Sun, Yinglu Jia, Jun Dai, Dhanusha T. N. Rathnayake, Xi Huang, Jade Casasent, Gopi Adhikari, Temban Acha Billy, Yongfeng Lu, Xiao Cheng Zeng, Yinsheng Guo
Summary: This study directly visualizes ferroelastic twin domains in lead halide perovskites and demonstrates their role as internal reflectors for energy transport. The findings show that these domain walls have low energies and can easily switch between different orientations, making them suitable for optical guiding of internal photoexcitations.
ADVANCED MATERIALS
(2023)
Article
Optics
Jian-Xin Wang, Luis Gutierrez-Arzaluz, Xiaojia Wang, Tengyue He, Yuhai Zhang, Mohamed Eddaoudi, Osman M. Bakr, Omar F. Mohammed
Summary: The research on organic X-ray imaging scintillators is an attractive direction for chemists, materials scientists, physicists and engineers. By introducing heavy atoms, researchers improved the X-ray absorption capability of scintillators while maintaining their unique TADF properties and high photoluminescence quantum yield. The X-ray screens fabricated using this method showed high resolution and sensitivity.
Article
Materials Science, Multidisciplinary
Jian-Xin Wang, Indranil Dutta, Jun Yin, Tengyue He, Luis Gutierrez-Arzaluz, Osman M. Bakr, Mohamed Eddaoudi, Kuo-Wei Huang, Omar F. Mohammed
Summary: In this study, a highly efficient and reabsorption-free transparent X-ray imaging scintillator was fabricated by utilizing an efficient triplet-triplet energy transfer strategy between TADF-Br and Ir-OMC. The experiments and calculations showed that efficient energy transfer from TADF-Br to Ir-OMC can be achieved, leading to enhanced triplet-state radioluminescence upon X-ray irradiation. The fabricated scintillator achieved a high X-ray imaging resolution of 19.8 lp mm -1 .
Article
Chemistry, Multidisciplinary
Ella Sanders, Yahel Soffer, Tommaso Salzillo, Maor Rosenberg, Omri Bar-Elli, Omer Yaffe, Ernesto Joselevich, Dan Oron
Summary: Metal halide perovskites (MHPs) exhibit unique characteristics and hold great potential in optoelectronic technologies. Research has shown that lattice strain and external electric fields play significant roles in optimizing device performance, with an interplay between the two offering new opportunities for the design of MHP-based optoelectronic nanodevices.
Article
Biochemical Research Methods
Md Inzamam Ul Haque, Debangshu Mukherjee, Sylwia A. Stopka, Nathalie Y. R. Agar, Jacob Hinkle, Olga S. Ovchinnikova
Summary: This study correlates H&E-stained biopsy data with MALDI mass-spectrometric imaging data to determine cancerous regions and their unique chemical signatures. The correlation between optical H&E features and chemical information in MSI allows for the prediction of prostate cancer with around 80% accuracy. Additionally, two chemical biomarkers were found to predict cancerous regions.
JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY
(2023)
Article
Chemistry, Multidisciplinary
Yongtao Liu, Jonghee Yang, Benjamin J. Lawrie, Kyle P. Kelley, Maxim Ziatdinov, Sergei V. Kalinin, Mahshid Ahmadi
Summary: The increasing photovoltaic efficiency and stability of metal halide perovskites (MHPs) are attributed to the improvement in understanding the microstructure of polycrystalline MHP thin films. A workflow combining conductive atomic force microscopy (AFM) measurement with a machine learning (ML) algorithm was designed to systematically investigate the grain boundaries in MHPs. This approach revealed that the properties of grain boundaries play critical roles in MHP stability.
Article
Chemistry, Physical
Yongtao Liu, Jonghee Yang, Rama K. Vasudevan, Kyle P. Kelley, Maxim Ziatdinov, Sergei Kalinin, Mahshid Ahmadi
Summary: We demonstrate an active machine learning framework for driving an automated scanning probe microscope (SPM) to discover the microstructures responsible for specific aspects of transport behavior in metal halide perovskites (MHPs). This approach allows the microscope to discover the microstructural elements that maximize the onset of conduction, hysteresis, or any other characteristic derived from a set of current-voltage spectra. It provides new opportunities for exploring the origins of materials functionality in complex materials by SPM and can be integrated with other characterization techniques.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2023)
Article
Nanoscience & Nanotechnology
Yong-Jin Kim, Minseo Kim, Yunae Cho, Sang Hee Lee, Dohyung Kim, Min Gu Kang, Hee-eun Song, Sungeun Park
Summary: This study investigates the optimal cell sorting method to minimize the deviation of module power in photovoltaic module manufacturing processes. Simulations are conducted considering solar cells with different electrical characteristics and ideal interconnections. The results show that sorting cells based on the average power maximum can significantly reduce the standard deviation of module power, providing useful guidance for reliable and cost-efficient photovoltaic module production.
Article
Chemistry, Physical
Yongtao Liu, Rama K. K. Vasudevan, Kyle P. Kelley, Hiroshi Funakubo, Maxim Ziatdinov, Sergei V. V. Kalinin
Summary: We developed automated experiment workflows for identifying the best predictive channel in spectroscopic measurements. The approach combines ensembled deep kernel learning for probabilistic predictions and reinforcement learning for channel selection. The implementation in multimodal imaging of piezoresponse force microscopy (PFM) showed that the amplitude is the best predictive channel for polarization-voltage and frequency-voltage hysteresis loop areas. This workflow and code can be applied to other multimodal imaging and local characterization methods.
NPJ COMPUTATIONAL MATERIALS
(2023)
Article
Computer Science, Artificial Intelligence
Yongtao Liu, Anna N. Morozovska, Eugene A. Eliseev, Kyle P. Kelley, Rama Vasudevan, Maxim Ziatdinov, Sergei V. Kalinin
Summary: Using hypothesis-learning-driven automated scanning probe microscopy (SPM), this study investigates the bias-induced transformations in various devices and materials. It is crucial to understand these mechanisms on the nanometer scale with a wide range of control parameters, which is experimentally challenging. The hypothesis-driven SPM autonomously identifies the mechanisms of bias-induced domain switching and reveals the importance of kinetic control.
Article
Computer Science, Artificial Intelligence
Sergei Kalinin, Rama Vasudevan, Yongtao Liu, Ayana Ghosh, Kevin Roccapriore, Maxim Ziatdinov
Summary: Microscopy provides an ideal experimental environment for the development and deployment of active Bayesian and reinforcement learning methods. By utilizing domain-specific deployable algorithms and static datasets, machine learning methods can be applied to microscopy and chemical imaging, accelerating real-world ML applications and scientific progress.
MACHINE LEARNING-SCIENCE AND TECHNOLOGY
(2023)
Article
Nanoscience & Nanotechnology
Holland Hysmith, So Yeon Park, Jonghee Yang, Anton V. Ievlev, Yongtao Liu, Kai Zhu, Bobby G. Sumpter, Joseph Berry, Mahshid Ahmadi, Olga S. Ovchinnikova
Summary: Moving towards a future of efficient, accessible, and less carbon-reliant energy devices has been a major focus of energy research innovations for the past three decades.The use of metal-halide perovskite (MHP) thin films has garnered significant attention due to their flexible device applications and tunable capabilities to enhance power conversion efficiency. A hybrid approach of chemical bath deposition (CBD) and nanoparticle SnO2 substrate processing has been found to greatly improve the performance of (FAPbI(3))(0.97)(MAPbBr(3))(0.03) by reducing micro-strain in the SnO2 lattice and allowing for the distribution of K+ ions to passivate defects at the interface. This results in higher current generation in both light and dark environments. Understanding the ion distribution at the SnO2 and perovskite interface can effectively reduce the formation of defects and promote more efficient MHP devices.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Chemistry, Multidisciplinary
Yongtao Liu, Anna N. Morozovska, Ayana Ghosh, Kyle P. Kelley, Eugene A. Eliseev, Jinyuan Yao, Ying Liu, Sergei Kalinin
Summary: In this study, the local curvature and strain effects on polarization in CIPS were investigated using piezoresponse force microscopy and spectroscopy. The finite element Landau-Ginzburg-Devonshire model was introduced to explain the observed behaviors and decouple the curvature and strain effects in 2D CIPS. The results showed that bending induced ferrielectric domains in CIPS and the polarization-voltage hysteresis loops differed in bending and nonbending regions. These studies provide important insights into the fabrication of curvature-engineered nanoelectronic devices.
Article
Chemistry, Physical
Dohyung Kim, Jae Sung Yun, Arun Sagotra, Alessandro Mattoni, Pankaj Sharma, Jincheol Kim, Da Seul Lee, Sean Lim, Padraic O'Reilly, Liz Brinkman, Martin A. Green, Shujuan Huang, Anita Ho-Baillie, Claudio Cazorla, Jan Seidel
Summary: The past decade has witnessed the rapid rise of a new class of solar cells based on mixed organic-inorganic halide perovskites. The power conversion efficiency of halide perovskite solar cells has exceeded 25% for single-junction devices and 30% for tandem devices. Twin domains within polycrystalline grains play important roles in ionic and charge carrier transport properties, although their mechanisms are not fully understood. This study combines molecular dynamic simulations and nanoscale scanning probe microscopy investigations to reveal unique properties of the twin domains that contribute to ion migration and influence charge separation and collection. The findings highlight the significance of nanoscale intragrain features for the development of high-efficiency perovskite solar cells.
JOURNAL OF MATERIALS CHEMISTRY A
(2023)
Article
Automation & Control Systems
Sheryl Sanchez, Yongtao Liu, Jonghee Yang, Sergei V. Kalinin, Maxim Ziatdinov, Mahshid Ahmadi
Summary: In recent years, laboratory automation and high-throughput synthesis and characterization have become increasingly important in the research community. To effectively analyze the large datasets and extract system properties, suitable machine learning techniques, such as the variational autoencoder (VAE) approach, are needed. This study explores the binary library of metal halide perovskite microcrystals using low-dimensional latent representations of photoluminescence spectra. The combination of translationally invariant variational autoencoders (tVAEs) and conditional autoencoders (cVAEs) allows for a deeper understanding of the underlying mechanisms within the data.
ADVANCED INTELLIGENT SYSTEMS
(2023)
Article
Materials Science, Multidisciplinary
Anna N. Morozovska, Eugene A. Eliseev, Yongtao Liu, Kyle P. Kelley, Ayana Ghosh, Ying Liu, Nicholas V. Morozovsky, Jinyuan Yao, Andrei L. Kholkin, Yulian M. Vysochanskii, Sergei V. Kalinin
Summary: Using the LGD approach, this study analyzed the redistribution of electric polarization and field, elastic stresses and strains inside ultrathin layers of van der Waals ferrielectrics induced by bending. The study focused on a CuInP2S6 (CIPS) thin layer with fixed edges and a suspended central part. The bending-induced isostructural transition between two ferrielectric states, FI1 and FI2, was found to occur in the layer, with the disappearance of edge FI2 states and the expansion of FI1 states near the inflection regions.
Article
Materials Science, Multidisciplinary
Leonard Jacques, Smitha Shetty, Fernando Josue Vega, Yongtao Liu, Benjamin Aronson, Thomas Beechem, Susan Trolier-McKinstry
Summary: The possibility of ferroelectricity in orthorhombic V2O5 thin films was investigated, and it was found that no evidence for ferroelectricity was observed, possibly due to trap states caused by oxygen vacancies affecting the observations.
MRS COMMUNICATIONS
(2023)
Article
Nanoscience & Nanotechnology
Yongtao Liu, Anton Ievlev, Joseph Casamento, John Hayden, Susan Trolier-McKinstry, Jon-Paul Maria, Sergei V. Kalinin, Kyle P. Kelley
Summary: By studying the dynamics of polarization and evolution of domain structure in ferroelectric Al0.93B0.07N, it was found that applying negative unipolar and bipolar reverse curve waveforms led to surface feature changes and a decrease in electromechanical response, while positive biases did not cause surface changes. Stable polarization patterns were observed in a controlled atmosphere, but even in this environment, surface ions may still participate in polarization switching phenomena and ionic compensation.
ADVANCED ELECTRONIC MATERIALS
(2023)
