Reducing the spatial inhomogeneity of solution-processed, multicrystalline methylammonium lead iodide (MAPbI) perovskite is of great importance for improving its power conversion efficiency, suppressing point-to-point deviations, and delaying degradation during operation. Various techniques, such as conducting-mode atomic force microscopy and photoluminescence mapping, have been applied for this intriguing class of materials, revealing nonuniform electronic properties on the nanometer-to-micrometer scale. Here, we designed a new space- and time-resolved microwave conductivity system that enables mapping of the transient photoconductivity with resolution greater than ∼45 μm. We examined the effects of the precursor concentration of MAPbI and the mixing of halides (I and Br) on the charge carrier dynamics, crystal size, and inhomogeneity of the films. The optoelectronic inhomogeneity of MAPbI and MAPb(I Br ) on the sub-millimeter and millimeter scales shows a general correlation with their crystallite sizes, whereas the precursor concentration and halide mixing affect the inhomogeneity in a different way, providing a basis for uniform processing of a multicrystalline perovskite film.
Download full-text PDF |
Source |
|---|---|
| http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6645387 | PMC |
| http://dx.doi.org/10.1021/acsomega.7b01471 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Superconductor-Insulator Transition Induced by Precise Subtripled Vapor Chemical Gating.
J Am Chem Soc
January 2025
State Key Laboratory of Precision and Intelligent Chemistry, CAS Key Laboratory of Mechanical Behavior and Design of Materials, University of Science and Technology of China, Hefei, Anhui 230026, P. R. China.
Recent progress in superconductor-insulator transition has shed light on the intermediate metallic state with unique electronic inhomogeneity. The microscopic model, suggesting that carrier spatial distribution plays a decisive role in the intermediate state, has been instrumental in understanding the quantum transition. However, the narrow carrier density window in which the intermediate state exists necessitates precise control of the gate dielectric layer, presenting a challenge to in situ map the carrier spatial distribution.
View Article and Find Full Text PDFCESTsimu: An open-source GUI for spectral and spatial CEST simulation.
Magn Reson Med
January 2025
Department of Diagnostic Radiology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China.
Purpose: The aim of this study was to create a user-friendly CEST simulation tool with a GUI for both spectral (1D Z-spectra) and spatial (2D phantom) CEST experiments, making the CEST simulation easier to perform.
Methods: CESTsimu was developed using MATLAB App Designer. It consists of three modules: Saturation Settings, Exchange Settings, and Phantom Settings.
Confocal Raman Microscopy with Adaptive Optics.
ACS Photonics
January 2025
Institute of Biomedical Physics, Medical University of Innsbruck, Müllerstraße 44, 6020 Innsbruck, Austria.
Confocal Raman microscopy, a highly specific and label-free technique for the microscale study of thick samples, often presents difficulties due to weak Raman signals. Inhomogeneous samples introduce wavefront aberrations that further reduce these signals, requiring even longer acquisition times. In this study, we introduce Adaptive Optics to confocal Raman microscopy for the first time to counteract such aberrations, significantly increasing the Raman signal and image quality.
View Article and Find Full Text PDFRemote epitaxial crystalline perovskites for ultrahigh-resolution micro-LED displays.
Nat Nanotechnol
January 2025
Key Laboratory of Bio-inspired Materials and Interfacial Science, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, China.
The miniaturization of light-emitting diodes (LEDs) is pivotal in ultrahigh-resolution displays. Metal-halide perovskites promise efficient light emission, long-range carrier transport and scalable manufacturing for bright microscale LED (micro-LED) displays. However, thin-film perovskites with inhomogeneous spatial distribution of light emission and unstable surface under lithography are incompatible with the micro-LED devices.
View Article and Find Full Text PDFEmergence of the North Pacific heat storage pattern delayed by decadal wind-driven redistribution.
Nat Commun
January 2025
Key Laboratory of Ocean Observation and Forecasting and Key Laboratory of Ocean Circulation and Waves, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China.
Storage of anthropogenic heat in the oceans is spatially inhomogeneous, impacting regional climates and human societies. Climate models project enhanced heat storage in the mid-latitude North Pacific (MNP) and much weaker storage in the tropical Pacific. However, the observed heat storage during the past half-century shows a more complex pattern, with limited warming in the MNP and enhanced warming in the northwest tropical Pacific.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!