Yazar "Satapathi, Soumitra" seçeneğine göre listele

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    Acetate-based ionic liquid engineering for efficient and stable CsPbI2Br perovskite solar cells with an unprecedented fill factor over 83%
    (Elsevier, 2024) Sadegh, Faranak; Ebic, Murat; Prochowicz, Daniel; Ans, Muhammad; Kruszynska, Joanna; Satapathi, Soumitra; Moghadam, Majid
    The current investigation addresses the persistent challenge of poor ambient stability exhibited by inorganic lead halide perovskites, primarily stemming from intrinsic phase transitions and the presence of defect states. This area of research has been considerably unexplored thus far. On the other hand, the notable effects of ionic liquids (ILs) in improving both stability and efficiency of perovskite photovoltaics have been substantial. In line with these developments, this study endeavors to synergize these two critical domains by introducing an acetate (Ac)based IL into the inorganic perovskite precursor solution to tailor the crystal growth and charge carrier dynamics in CsPbI2Br films, resulting in prolonged stability and enhanced photovoltaic performance. The integration of 1-butyl-3-methylimidazolium acetate (BMIMAc) can indeed accelerate the crystallization of the inorganic perovskite film by interacting the Ac anion with uncoordinated Pb2+ cation in CsPbI2Br. This interaction prompts the formation of smaller grains, which in turn inhibits the creation of non-photoactive phases. Moreover, the presence of BMIMAc as a passivation agent introduces significant defect-healing capabilities, eliminated charge recombination, and increased hydrophobicity. This work endeavors to pave the way for high-efficiency, enduring, and more robust inorganic PSCs through the integration of innovative materials and advanced understanding of fundamental principles, resulting uniform and dense perovskite film. Accordingly, 1.1 mol% BMIMAc-passivated device enables an impressive efficiency of 15.6% with an unprecedented fill factor (FF) exceeding 83%. Remarkably, even after undergoing extended light-soaking for 600 h, the BMIMAc-passivated device retains approximately 85% of its initial efficiency.
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    Deconvoluting the Impedance Response of Halide Perovskite Single Crystals: The Distribution of Relaxation Time Method
    (Amer Chemical Soc, 2023) Pandey, Siddhi Vinayak; Parikh, Nishi; Mahapatra, Apurba; Kalam, Abul; Akin, Seckin; Satapathi, Soumitra; Prochowicz, Daniel
    Electrochemical impedance spectroscopy (EIS) has beenemergingas a promising tool to study the core mechanisms occurring withinmetal halide perovskites (MHPs). Generally, MHPs show one or two semicirclesin the Nyquist spectra in the probed frequency range. However, inthe presence of external stimuli, often a Warburg diffusion or aninductive loop is observed at low frequencies. In such cases, a comparisonof low-frequency parameters in both cases cannot be drawn becauseof the lack of a unique electrical circuit (EC). To overcome the issueof lack of EC, transformation of the frequency-domain technique tothe time domain is carried out. In this work, we investigated threedifferent cases of MAPbI(3), MAPbBr(3), and surface-passivatedMAPbBr(3) single crystals (SCs), which showed one suppressedsemicircle, two semicircles, and a Warburg-like diffusion, respectively,in the Nyquist response of EIS. Next, we transformed these spectrainto the time domain using the distribution of relaxation times (DRT)technique, a machine-learning-assisted tool. The obtained resultssuggest that in the case of Nyquist spectra with one semicircle (thecase of MAPbI(3) SCs), the observed time constants usingEC and DRT are close enough. However, in the case of MAPbBr(3) SC, three different time constants are obtained, associated withhigh, medium, and low frequencies, although the Nyquist response showedtwo semicircles. At last, in the presence of surface-passivated SCs,the Warburg-like feature changes significantly for different passivationtimes. Interestingly, the DRT spectra showed almost similar time constants,through which reliable information on the low-frequency RC can beextracted. Thus, DRT can pave the way for the easy and reliable interpretationof EIS spectra, which is not possible using EC.