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Cari tutti,

vi ricordiamo l'incontro SMeet di venerdì 10 Giugno  alle ore 11:30 (l'ammissione in stanza dalle ore 11:20). Qui di seguito vi é il link MS Teams per accedere al Meeting: http://bit.ly/SMEET-IMM

Il meeting prevede:

* Speaker: Dott. Damiano Ricciarelli
* Chair: Dott. Giuseppe Fisicaro
* Titolo: Origin of limitations in Tin Iodide Perovskites solar cells performances and possible healing strategies.
Abstract: Lead-halide perovskites are outstanding materials for photovoltaics, providing efficiencies of > 25 % in solar cells devices.1 The presence of lead, however, is raising serious concerns about potential treats to living organisms.2 The full replacement of Pb by Sn in MASnI3 (MA = Methylammonium) has been demonstrated to be an effective strategy,3 however, the performance of the resulting devices is limited by uncontrollable self p-doping and rapid degradation of the lattice into optically inactive tin(IV) phases.4
Due to the raising interest in these materials, we performed an extensive ab-initio defect chemistry analysis to understand the atomistic origins behind the poor performances of tin iodide perovskite solar cells. In doing so, we identify significant differences with MAPbI3 ascribed to the larger oxidation potential of MASnI3 and we show that tin vacancies can be easily formed in the latter, being the main responsible of the severe p-doping.5 We then understand, by means of simple models, that the oxidation of tin(II) into tin(IV) occurs mainly on the surface of the material, promoted by the presence of low coordinated Sn units.5-6
Thus, stabilizing tin-iodide perovskites may seem a desperate case because of the two (bulk and surface) oxidation channels related to the high band edge energetics. We finally illustrate possible strategies aimed at mitigating MASnI3 instability through tailored substitution of tin and iodine, with isovalent and aliovalent metals (B-site doping) and with different halides.

Vi aspettiamo numerosi,

Saluti
 

SMeet – Comitato Organizzativo
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Web-page: https://hq.imm.cnr.it/smeet-science-sharing-meetings