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Control over grain size and crystallinity is important for preparation of methylammonium lead iodide (MAPbI) solar cells. We explore the effects of using small concentrations of Cd and unusually high concentrations of methylammonium iodide during the growth of MAPbI in the two-step solution process. In addition to improved crystallinity and an enhancement in the size of the grains, time-resolved photoluminescence measurements indicated a dramatic increase in the carrier lifetime. As a result, devices constructed with the Cd-modified perovskites showed nearly a factor of 2 improvement in the power conversion efficiency (PCE) relative to similar devices prepared without Cd addition. The grains also showed a higher degree of orientation in the ⟨110⟩ direction, indicating a change in the growth mechanism, and the films were compact and smooth. We propose a Cd-modified film growth mechanism that invokes a critical role for low-dimensional Cd perovskites to explain the experimental observations.
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http://dx.doi.org/10.1021/acsami.6b12627 | DOI Listing |
Environ Pollut
September 2025
State Key Laboratory of Loess Science, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an, 710061, China. Electronic address:
This study investigates the vertical profiles, pollution status and ecological risks of heavy metal(loid)s contamination in three sediment cores (N21, N03, and 38002) from the North Yellow Sea (NYS), with a focus on the influence of grain size effects on sedimentary profiles. The results revealed distinct vertical distribution patterns of heavy metal(loid)s content among the three sediment cores. Enrichment Factor (EF) and Geo-accumulation Index (I) assessments identified Sb as significantly enriched, indicating anthropogenic influence, whereas Co, Cr, Cu, Ni, and Zn primarily originated from natural weathering.
View Article and Find Full Text PDFJ Phys Chem Lett
September 2025
Shandong Province Key Laboratory of Medical Physics and Image Processing Technology, School of Physics and Electronics, Shandong Normal University, Jinan 250014, P.R. China.
Metal halide perovskites have garnered significant attention due to their exceptional photoelectric properties. The alkali metal doping strategy has been demonstrated to effectively modulate grain size, control crystallization kinetics, and adjust band gap characteristics in perovskite. This study employs the first-principles calculations to reveal that the selection of alkali metal species and their corresponding doping methodologies exert markedly distinct influences on both the electronic properties and ion migration kinetics of CsPbBr perovskites.
View Article and Find Full Text PDFACS Appl Mater Interfaces
September 2025
School of Materials Science and Engineering, Beihang University, Beijing 100191, P. R. China.
Nanostructured cubic boron nitride (NS-cBN) has attracted significant attention due to its high hardness and excellent thermal stability, yet a systematic strategy to balance strength and toughness through atomically structural design remains elusive. Here, we integrate plasticity theory with large-scale atomistic simulations to elucidate the size-dependent roles of internal defects, i.e.
View Article and Find Full Text PDFInt J Radiat Biol
September 2025
Department of Geography, Nara Women's University, Nara, Japan.
Purpose: The number of oxygen vacancies in quartz measured by electron spin resonance (ESR) as the intensity of the E' center has been used to investigate the provenance of the sediments and has been found to be a good proxy in discussing the direction and intensity of the wind system in the past. While its temporal variations have been examined using marine sediments. The present study aimed to show that terrestrial sediments are also useful for such studies on climate change when it is continuous.
View Article and Find Full Text PDFAdv Mater
September 2025
Key Lab of Artificial Micro- and Nano-Structures of Ministry of Education of China, School of Physics and Technology, Wuhan University, Wuhan, 430072, China.
Sequential deposition technique is widely used to fabricate perovskite films with large grain size in perovskite solar cells (PSCs). Residual lead halide (PbI) in the perovskite film tends to be decomposed into metallic lead (Pb) under long-term heating or light soaking. Here, a chiral levetiracetam (LEV) dopant containing α-amide and pyrrolidone groups is introduced into the PbI precursor solution.
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