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5. Temporal Evolution of Self-Assembled Lead Halide Perovskite Nanocrystal Superlattices: Effects on Photoluminescence and Energy Transfer

Author

Baranov, Dmitry, Fieramosca, Antonio, Yang, Ruo Xi, Polimeno, Laura, Lerario, Giovanni, Toso, Stefano, Giansante, Carlo, De Giorgi, Milena, Tan, Liang Z., Sanvitto, Daniele, and Manna, Liberato

Subjects
Physics - Applied Physics, Condensed Matter - Mesoscale and Nanoscale Physics, Condensed Matter - Materials Science
Abstract

Excitonic/electronic coupling and cooperative interactions in self-assembled lead halide perovskite nanocrystals were reported to give rise to a collective low energy emission peak with accelerated dynamics. Here we report that similar spectroscopic features could appear as a result of the nanocrystal reactivity within the self-assembled superlattices. This is demonstrated by using CsPbBr3 nanocrystal superlattices under room temperature and cryogenic micro-photoluminescence spectroscopy. It is shown that keeping such structures under vacuum, a gradual contraction of the superlattices and subsequent coalescence of the nanocrystals occurs over several days. As a result, a narrow, low energy emission peak is observed at 4 K with a concomitant shortening of the photoluminescence lifetime due to the energy transfer between nanocrystals. When exposed to air, self-assembled CsPbBr3 nanocrystals develop bulk-like CsPbBr3 particles on top of the superlattices. At 4 K, these particles produce a distribution of narrow, low energy emission peaks with short lifetimes and excitation fluence-dependent, oscillatory decays, resembling the features of superfluorescence. Overall, the reactivity of CsPbBr3 nanocrystals dramatically alters the emission of their assemblies, which should not be overlooked when studying collective optoelectronic properties nor confused with superfluorescence effects., Comment: 50 pages, 26 figures

Published
2020
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6. Bandgap in orthorhombic thin lead halide perovskite (CsPbBr3) nanosheets measured from STEM-EELS

Author

Brescia, Rosaria, Toso, Stefano, Ramasse, Quentin, Manna, Liberato, Downing, Clive, Calzolari, Arrigo, and Bertoni, Giovanni

Subjects
Condensed Matter - Materials Science
Abstract

Inorganic lead halide perovskites are promising candidates for optoelectronic applications, due to their bandgap tunability, high photoluminescence quantum yield, and narrow emission line widths. In particular, they offer the possibility to vary the bandgap as a function of the halide composition and dimension/shape of the crystals at the nanoscale. Here we present an aberration-corrected scanning transmission microscopy (STEM) study of extended nanosheets of CsPbBr3 directly demonstrating their orthorhombic crystal structure and their lateral termination with Cs-Br planes. The bandgaps from individual nanosheets are measured by monochromated electron energy loss spectroscopy (EELS). We find an increase of the bandgap starting at thicknesses below 10 nm, confirming the less dramatic effect of 1D confinement in nanosheets compared to the 3D confinement observed in quantum dots, as predicted by density functional theory calculations and optical spectroscopy data from ensemble measurements.

Published
2020
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7. Multilayer Diffraction Reveals That Colloidal Superlattices Approach the Structural Perfection of Single Crystals

Author

Toso, Stefano, Baranov, Dmitry, Altamura, Davide, Scattarella, Francesco, Dahl, Jakob, Wang, Xingzhi, Marras, Sergio, Alivisatos, A Paul, Singer, Andrej, Giannini, Cinzia, and Manna, Liberato

Subjects
Macromolecular and Materials Chemistry, Chemical Sciences, nanocrystal, superlattice, multilayer diffraction, disorder, grazing-incidence, thermal annealing, Nanoscience & Nanotechnology
Abstract

Colloidal superlattices are fascinating materials made of ordered nanocrystals, yet they are rarely called "atomically precise". That is unsurprising, given how challenging it is to quantify the degree of structural order in these materials. However, once that order crosses a certain threshold, the constructive interference of X-rays diffracted by the nanocrystals dominates the diffraction pattern, offering a wealth of structural information. By treating nanocrystals as scattering sources forming a self-probing interferometer, we developed a multilayer diffraction method that enabled the accurate determination of the nanocrystal size, interparticle spacing, and their fluctuations for samples of self-assembled CsPbBr3 and PbS nanomaterials. The multilayer diffraction method requires only a laboratory-grade diffractometer and an open-source fitting algorithm for data analysis. The average nanocrystal displacement of 0.33 to 1.43 Å in the studied superlattices provides a figure of merit for their structural perfection and approaches the atomic displacement parameters found in traditional crystals.

Published
2021

8. Aging of Self-Assembled Lead Halide Perovskite Nanocrystal Superlattices: Effects on Photoluminescence and Energy Transfer

Author

Baranov, Dmitry, Fieramosca, Antonio, Yang, Ruo Xi, Polimeno, Laura, Lerario, Giovanni, Toso, Stefano, Giansante, Carlo, De Giorgi, Milena, Tan, Liang Z, Sanvitto, Daniele, and Manna, Liberato

Subjects
Macromolecular and Materials Chemistry, Chemical Sciences, Physical Chemistry, Affordable and Clean Energy, perovskite nanocrystals, self-assembly, nanocrystal superlattices, environmental stability, reactivity, low-temperature photoluminescence, energy transfer, physics.app-ph, cond-mat.mes-hall, cond-mat.mtrl-sci, Nanoscience & Nanotechnology
Abstract

Excitonic coupling, electronic coupling, and cooperative interactions in self-assembled lead halide perovskite nanocrystals were reported to give rise to a red-shifted collective emission peak with accelerated dynamics. Here we report that similar spectroscopic features could appear as a result of the nanocrystal reactivity within the self-assembled superlattices. This is demonstrated by studying CsPbBr3 nanocrystal superlattices over time with room-temperature and cryogenic micro-photoluminescence spectroscopy, X-ray diffraction, and electron microscopy. It is shown that a gradual contraction of the superlattices and subsequent coalescence of the nanocrystals occurs over several days of keeping such structures under vacuum. As a result, a narrow, low-energy emission peak is observed at 4 K with a concomitant shortening of the photoluminescence lifetime due to the energy transfer between nanocrystals. When exposed to air, self-assembled CsPbBr3 nanocrystals develop bulk-like CsPbBr3 particles on top of the superlattices. At 4 K, these particles produce a distribution of narrow, low-energy emission peaks with short lifetimes and excitation fluence-dependent, oscillatory decays. Overall, the aging of CsPbBr3 nanocrystal assemblies dramatically alters their emission properties and that should not be overlooked when studying collective optoelectronic phenomena nor confused with superfluorescence effects.

Published
2021

12. Direct Band Gap Chalcohalide Semiconductors: Quaternary AgBiSCl2 Nanocrystals

Author

Quarta, Danila, primary, Toso, Stefano, additional, Fieramosca, Antonio, additional, Dominici, Lorenzo, additional, Caliandro, Rocco, additional, Moliterni, Anna, additional, Tobaldi, David Maria, additional, Saleh, Gabriele, additional, Gushchina, Irina, additional, Brescia, Rosaria, additional, Prato, Mirko, additional, Infante, Ivan, additional, Cola, Adriano, additional, Giannini, Cinzia, additional, Manna, Liberato, additional, Gigli, Giuseppe, additional, and Giansante, Carlo, additional

Published
2023
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17. Semen Analysis in “Urology-Naïve” Patients: A Chance of Uroandrological Screening in Young Males

Author

Puliatti, Stefano, primary, Toso, Stefano, additional, Ticonosco, Marco, additional, Rabito, Salvatore, additional, Sighinolfi, Maria Chiara, additional, Ferrari, Riccardo, additional, Rochira, Vincenzo, additional, Santi, Daniele, additional, Trenti, Tommaso, additional, Navarra, Michele, additional, Ferretti, Stefania, additional, Montano, Luigi, additional, and Micali, Salvatore, additional

Published
2023
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19. ONE, TWO, MANY NANOCRYSTALS: CHARACTERIZING LEAD HALIDE NANOSTRUCTURES FROM SINGLEPARTICELES TO BULK

Author

TOSO, STEFANO, GAVIOLI, LUCA, LIBERATO, MANNA, and MASARU, KUNO

Subjects
CHIMICA GENERALE E INORGANICA [CHIM/03], CHIMICA FISICA [CHIM/02], FISICA DELLA MATERIA [FIS/03], Nanocrystal, Superlattice, Diffraction, Structure, Semiconductor, Nanomaterial, Perovskite, Nanocristallo, Superreticolo, Diffrazione, Struttura, Semiconduttore, Nanomateriale
Abstract

Negli ultimi decenni la chimica colloidale ha prodotto una crescente varietà di nanostrutture inorganiche con proprietà variegate e finemente regolabili, che possono essere ottimizzate per diverse applicazioni. Tuttavia, questa varietà complica la caratterizzazione strutturale dei nanomateriali, le cui piccole dimensioni e l’intrinseca complessità impongono limitazioni tecniche. Questa Tesi ha come obiettivo quello di affrontare tali sfide proponendo nuovi approcci per caratterizzare e descrivere la struttura dei nanomateriali, approcci che sono qui applicati su nanostrutture di semiconduttori piombo-alogeno. Questi materiali sono molto studiati per le loro interessanti proprietà e per la diversità strutturale che esprimono alla nanoscala, e per questo offrono molti interrogativi scientifici. Sono qui discussi quattro casi studio, ciascuno caratterizzato da una crescente complessità. I) La scoperta di nuovi calcoalogenuri di piombo sotto forma di nanocristalli è sfruttata per sperimentare strategie di soluzione strutturale per nanomateriali inorganici basate sull’utilizzo combinato di tecniche di diffrazione a raggi X ed elettroniche. Sono proposte linee guida per ogni fase del processo di soluzione strutturale, dalla determinazione della stechiometria, all’indicizzazione della cella, fino al raffinamento della struttura. II) Viene discusso come le trasformazioni chimiche tra nanocristalli di alogenuri di piombo-cesio prevedano la formazione di dimeri epitassiali come intermedi di reazione, la cui formazione dipende da specifiche relazioni strutturali. Sulla base di questa scoperta, si dimostra che la formazione di eterostrutture epitassiali tra perovskiti e calcoalogenuri può essere sfruttata efficacemente per indirizzare la sintesi fase-selettiva di nanocristalli colloidali. III) Viene proposto un nuovo metodo per caratterizzare la struttura di solidi formati da nanocristalli auto-assemblati, qui dimostrato su superreticoli di nanocristalli di perovskiti piombo-alogeno. Tale metodo si basa su tecniche di diffrazione sviluppate per film sottili multistrato cresciuti tramite metodi fisici, e sfrutta l'analisi di fenomeni di interferenza collettiva nella regione ad alti angoli del diffrattogramma a raggi X del campione. IV) Campioni microcristallini di perovskiti Ruddlesden-Popper, che sono alogenuri ibridi composti da strati organici e inorganici nanoscopici ordinatamente impilati, sono studiati tramite un'analisi geometrica dei loro parametri di cella per determinare come alogenuri diversi si dispongano disomogeneamente all'interno della struttura cristallina del materiale., Over the past few decades colloidal chemistry has provided access to a growing variety of inorganic nanostructures with diverse and customizable properties, which can be tailored to many different applications. However, such diversity presents challenges when it comes to characterizing the structure of functional nanomaterials, where the small size and the increased complexity impose technical limitations. This Thesis aims to address these challenges by developing novel approaches to characterize and describe the structure of nanomaterials, which are here demonstrated on lead halide semiconductor nanostructures. These materials are widely investigated for their appealing properties and the structural diversity they express at the nanoscale, and pose therefore a variety of compelling scientific questions. Here are discussed four case studies, each characterized by increasing nanoscale complexity. I) Colloidal nanocrystals of previously unknown lead chalcohalide phases are used to demonstrate strategies for solving the structure of novel inorganic materials by means of combined electron and X-ray diffraction techniques. Guidelines are proposed for each step of the structure solution process, from the stoichiometry determination to the cell indexation and the final structure refinement. II) Epitaxial dimers formed by cesium lead halide compounds are rationalized as reaction intermediates in the chemical transformation of colloidal nanocrystals, and the structural relationships enabling their formation are explored. Following this lead, perovskite/chalcohalide heterostructures are demonstrated as effective templates for the phase-selective synthesis of colloidal nanocrystals. III) Superlattices of lead halide perovskite nanocrystals are used to develop a novel approach for characterizing the nanoscale structure of self-assembled nanocrystal solids. This method is based on diffraction techniques developed for multilayer thin films grown by physical methods, and relies on the analysis of collective interference phenomena in the wide-angle X-ray diffraction pattern of samples. IV) Microcrystalline samples of hybrid layered Ruddlesden-Popper perovskites, composed by nanoscale stacks of organic and inorganic layers, are investigated through a geometric analysis of their unit cell parameters to determine the inhomogeneous distribution of different halides alloyed within their structure.

Published
2023

21. Mixed Valence of Bismuth in Hexagonal Chalcohalide Nanocrystals

Author

Quarta, Danila, primary, Toso, Stefano, additional, Saleh, Gabriele, additional, Caliandro, Rocco, additional, Moliterni, Anna, additional, Griesi, Andrea, additional, Divitini, Giorgio, additional, Infante, Ivan, additional, Gigli, Giuseppe, additional, Giannini, Cinzia, additional, Manna, Liberato, additional, and Giansante, Carlo, additional

Published
2023
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22. One-year outcomes after water vapor thermal therapy for symptomatic benign prostatic hyperplasia in an unselected Italian multicenter cohort

Author

CINDOLO, Luca, primary, MORSELLI, Simone, additional, CAMPOBASSO, Davide, additional, CONTI, Enrico, additional, SEBASTIANI, Giancarlo, additional, FRANZOSO, Francesco, additional, GALLUCCIO, Giuseppe, additional, MARUZZI, Daniele, additional, VISALLI, Francesco, additional, VARVELLO, Francesco, additional, LUCCI CHIARISSI, Marco, additional, VIOLA, Lorenzo, additional, SESSA, Francesco, additional, TOSO, Stefano, additional, MICALI, Salvatore, additional, FERRARI, Giovanni, additional, and SIENA, Giampaolo, additional

Published
2023
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27. Cu+ → Mn2+ Energy Transfer in Cu, Mn Coalloyed Cs3ZnCl5 Colloidal Nanocrystals

Author

Liu, Ying, primary, Zaffalon, Matteo L., additional, Zito, Juliette, additional, Cova, Francesca, additional, Moro, Fabrizio, additional, Fanciulli, Marco, additional, Zhu, Dongxu, additional, Toso, Stefano, additional, Xia, Zhiguo, additional, Infante, Ivan, additional, De Trizio, Luca, additional, Brovelli, Sergio, additional, and Manna, Liberato, additional

Published
2022
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29. CsPbCl3→ CsPbI3Exchange in Perovskite Nanocrystals Proceeds through a Jump-the-Gap Reaction Mechanism

Author

Livakas, Nikolaos, Toso, Stefano, Ivanov, Yurii P., Das, Tisita, Chakraborty, Sudip, Divitini, Giorgio, and Manna, Liberato

Abstract

Halide exchange is a popular strategy to tune the properties of CsPbX3nanocrystals after synthesis. However, while Cl → Br and Br → I exchanges proceed through the formation of stable mixed-halide nanocrystals, the Cl ⇌ I exchange is more elusive. Indeed, the large size difference between chloride and iodide ions causes a miscibility gap in the CsPbCl3–CsPbI3system, preventing the isolation of stable CsPb(ClxI1–x)3nanocrystals. Yet, previous works have claimed that a full CsPbCl3→ CsPbI3exchange can be achieved. Even more interestingly, interrupting the exchange prematurely yields a mixture of CsPbCl3and CsPbI3nanocrystals that coexist without undergoing further transformation. Here, we investigate the reaction mechanism of CsPbCl3→ CsPbI3exchange in nanocrystals. We show that the reaction proceeds through the early formation of iodide-doped CsPbCl3nanocrystals covered by a monolayer shell of CsI. These nanocrystals then leap over the miscibility gap between CsPbCl3and CsPbI3by briefly transitioning to short-lived and nonrecoverable CsPb(ClxI1–x)3nanocrystals, which quickly expel the excess chloride and turn into the chloride-doped CsPbI3nanocrystals found in the final product.

Published
2023
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30. Halide Perovskites as Disposable Epitaxial Templates for the Phase-Selective Synthesis of Lead Sulfochloride Nanocrystals

Author

Toso, Stefano, primary, Imran, Muhammad, additional, Mugnaioli, Enrico, additional, Moliterni, Anna, additional, Caliandro, Rocco, additional, Schrenker, Nadine J., additional, Pianetti, Andrea, additional, Zito, Juliette, additional, Zaccaria, Francesco, additional, Wu, Ye, additional, Gemmi, Mauro, additional, Giannini, Cinzia, additional, Brovelli, Sergio, additional, Infante, Ivan, additional, Bals, Sara, additional, and Manna, Liberato, additional

Published
2022
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32. Colloidal Bismuth Chalcohalide Nanocrystals

Author

Quarta, Danila, primary, Toso, Stefano, additional, Giannuzzi, Roberto, additional, Caliandro, Rocco, additional, Moliterni, Anna, additional, Saleh, Gabriele, additional, Capodilupo, Agostina‐Lina, additional, Debellis, Doriana, additional, Prato, Mirko, additional, Nobile, Concetta, additional, Maiorano, Vincenzo, additional, Infante, Ivan, additional, Gigli, Giuseppe, additional, Giannini, Cinzia, additional, Manna, Liberato, additional, and Giansante, Carlo, additional

Published
2022
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35. Psychological distress among patients awaiting histopathologic results after prostate biopsy: An unaddressed concern

Author

Sarchi, Luca, primary, Eissa, Ahmed, additional, Puliatti, Stefano, additional, Amato, Marco, additional, Assumma, Simone, additional, Calcagnile, Tommaso, additional, Ticonosco, Marco, additional, Iseppi, Andrea, additional, Toso, Stefano, additional, Sighinolfi, Maria Chiara, additional, Bianchi, Giampaolo, additional, Micali, Salvatore, additional, and Rocco, Bernardo, additional

Published
2021
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41. Psychological distress among patients awaiting histopathologic results after prostate biopsy: An unaddressed concern.

Author

Sarchi, Luca, Eissa, Ahmed, Puliatti, Stefano, Amato, Marco, Assumma, Simone, Calcagnile, Tommaso, Ticonosco, Marco, Iseppi, Andrea, Toso, Stefano, Sighinolfi, Maria Chiara, Bianchi, Giampaolo, Micali, Salvatore, and Rocco, Bernardo

Subjects
PSYCHOLOGICAL distress, PROSTATE biopsy, PSYCHOLOGICAL factors, HOSPITAL patients, PSYCHOMETRICS
Abstract

Background: Prostate cancer is the most commonly diagnosed neoplasm in men. From the introduction of PSA testing, an increasing number of men undergoes prostate biopsy (PBX). While the physical side effects of PBx have been well investigated, its psychological impact has been under-evaluated. Aim: The aim of our study is to investigate the presence of psychological distress (anxiety and depression) in patients waiting for histopathological results after prostate biopsy (PBx). Methods: From February to April 2019, 51 consecutive patients undergoing prostate biopsies at our institution were included. Age, PSA, DRE, familiarity for prostate cancer, number of previous biopsies, type of anesthesia, number of cores were recorded. All patients filled the Hospital Anxiety and Depression Scale (HADS), a psychometric Likert-scale questionnaire, before receiving the histopathological results of their PBx. Results: The prevalence of psychological distress among patients awaiting histopathologic results is 41% (21/51 patients), with anxiety being the main component of their distress. On multivariate analysis, PSA, family history, and repeat biopsy were significantly associated with anxiety and depression. Conclusion: Patients undergoing PBx experience a burden of psychological distress waiting for histopathologic results, especially anxiety. Appropriate counseling should be offered to patients at high risk of developing psychological distress after PBx. Future goals would include technological improvements to shorten the time between biopsy and definitive results. [ABSTRACT FROM AUTHOR]

Published
2022
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43. Halide Perovskite–Lead Chalcohalide Nanocrystal Heterostructures

Author

Imran, Muhammad, primary, Peng, Lucheng, additional, Pianetti, Andrea, additional, Pinchetti, Valerio, additional, Ramade, Julien, additional, Zito, Juliette, additional, Di Stasio, Francesco, additional, Buha, Joka, additional, Toso, Stefano, additional, Song, Jun, additional, Infante, Ivan, additional, Bals, Sara, additional, Brovelli, Sergio, additional, and Manna, Liberato, additional

Published
2021
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45. Le patologie del surrene

Author

Puliatti, Stefano, Eissa, Ahmed, Amato, Marco, Toso, Stefano, and Mottrie, Alexandre

Published
2020

46. Aging of Self-Assembled Lead Halide Perovskite Nanocrystal Superlattices: Effects on Photoluminescence and Energy Transfer

Author

Baranov, Dmitry, primary, Fieramosca, Antonio, additional, Yang, Ruo Xi, additional, Polimeno, Laura, additional, Lerario, Giovanni, additional, Toso, Stefano, additional, Giansante, Carlo, additional, Giorgi, Milena De, additional, Tan, Liang Z., additional, Sanvitto, Daniele, additional, and Manna, Liberato, additional

Published
2020
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50. Suppressing Cation Migration in Triple-Cation Lead Halide Perovskites

Author

Pavlovetc, Ilia M., primary, Brennan, Michael C., additional, Draguta, Sergiu, additional, Ruth, Anthony, additional, Moot, Taylor, additional, Christians, Jeffrey A., additional, Aleshire, Kyle, additional, Harvey, Steven P., additional, Toso, Stefano, additional, Nanayakkara, Sanjini U., additional, Messinger, Jonah, additional, Luther, Joseph M., additional, and Kuno, Masaru, additional

Published
2020
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