| Records |
| Author |
Imran, M.; Ramade, J.; Di Stasio, F.; De Franco, M.; Buha, J.; Van Aert, S.; Goldoni, L.; Lauciello, S.; Prato, M.; Infante, I.; Bals, S.; Manna, L. |
| Title |
Alloy CsCdxPb1–xBr3Perovskite Nanocrystals: The Role of Surface Passivation in Preserving Composition and Blue Emission |
Type |
A1 Journal article |
| Year |
2020 |
Publication |
Chemistry Of Materials |
Abbreviated Journal |
Chem Mater |
| Volume |
32 |
Issue |
|
Pages |
acs.chemmater.0c03825 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
Various strategies have been proposed to engineer the band gap of metal halide perovskite nanocrystals (NCs) while preserving their structure and composition and thus ensuring spectral stability of the emission color. An aspect that has only been marginally investigated is how the type of surface passivation influences the structural/color stability of AMX3 perovskite NCs composed of two different M2+ cations. Here, we report the synthesis of blue-emitting Cs-oleate capped CsCdxPb1–xBr3 NCs, which exhibit a cubic perovskite phase containing Cd-rich domains of Ruddlesden–Popper phases (RP phases). The RP domains spontaneously transform into pure orthorhombic perovskite ones upon NC aging, and the emission color of the NCs shifts from blue to green over days. On the other hand, postsynthesis ligand exchange with various Cs-carboxylate or ammonium bromide salts, right after NC synthesis, provides monocrystalline NCs with cubic phase, highlighting the metastability of RP domains. When NCs are treated with Cs-carboxylates (including Cs-oleate), most of the Cd2+ ions are expelled from NCs upon aging, and the NCs phase evolves from cubic to orthorhombic and their emission color changes from blue to green. Instead, when NCs are coated with ammonium bromides, the loss of Cd2+ ions is suppressed and the NCs tend to retain their blue emission (both in colloidal dispersions and in electroluminescent devices), as well as their cubic phase, over time. The improved compositional and structural stability in the latter cases is ascribed to the saturation of surface vacancies, which may act as channels for the expulsion of Cd2+ ions from NCs. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
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Wos |
000603288800034 |
Publication Date |
2020-12-04 |
| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
|
Series Issue |
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Edition |
|
| ISSN |
0897-4756 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor  |
8.6 |
Times cited |
44 |
Open Access |
OpenAccess |
| Notes |
European Commission; Fonds Wetenschappelijk Onderzoek, G.0267.18N ; H2020 European Research Council, 770887 815128 851794 ; We acknowledge funding from the FLAG-ERA JTC2019 project PeroGas. S.B., and S.V.A. acknowledges funding from the European Research Council under the European Union’s Horizon 2020 research and innovation program (ERC Consolidator Grants #815128REALNANO and #770887PICOMETRICS) and from the Research Foundation Flanders (FWO, Belgium) through project funding G.0267.18N. F.D.S. acknowledges the funding from ERC starting grant NANOLED (851794). The computational work was carried out on the Dutch National e-infrastructure with the support of the SURF Cooperative; sygma |
Approved |
Most recent IF: 8.6; 2020 IF: 9.466 |
| Call Number |
EMAT @ emat @c:irua:174004 |
Serial |
6659 |
| Permanent link to this record |
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| Author |
Hao, Y.; Velpula, G.; Kaltenegger, M.; Bodlos, W.R.; Vibert, F.; Mali, K.S.; De Feyter, S.; Resel, R.; Geerts, Y.H.; Van Aert, S.; Beljonne, D.; Lazzaroni, R. |
| Title |
From 2D to 3D : bridging self-assembled monolayers to a substrate-induced polymorph in a molecular semiconductor |
Type |
A1 Journal article |
| Year |
2022 |
Publication |
Chemistry of materials |
Abbreviated Journal |
Chem Mater |
| Volume |
34 |
Issue |
5 |
Pages |
2238-2248 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
In this study, a new bottom-up approach is proposed to predict the crystal structure of the substrate-induced polymorph (SIP) of an archetypal molecular semiconductor. In spite of intense efforts, the formation mechanism of SIPs is still not fully understood, and predicting their crystal structure is a very delicate task. Here, we selected lead phthalocyanine (PbPc) as a prototypical molecular material because it is a highly symmetrical yet nonplanar molecule and we demonstrate that the growth and crystal structure of the PbPc SIPs can be templated by the corresponding physisorbed self-assembled molecular networks (SAMNs). Starting from SAMNs of PbPc formed at the solution/graphite interface, the structural and energetic aspects of the assembly were studied by a combination of in situ scanning tunneling microscopy and multiscale computational chemistry approach. Then, the growth of a PbPc SIP on top of the physisorbed monolayer was modeled without prior experimental knowledge, from which the crystal structure of the SIP was predicted. The theoretical prediction of the SIP was verified by determining the crystal structure of PbPc thin films using X-ray diffraction techniques, revealing the formation of a new polymorph of PbPc on the graphite substrate. This study clearly illustrates the correlation between the SAMNs and SIPs, which are traditionally considered as two separate but conceptually connected research areas. This approach is applicable to molecular materials in general to predict the crystal structure of their SIPs. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
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Wos |
000812125800001 |
Publication Date |
2022-02-17 |
| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
|
| ISSN |
0897-4756; 1520-5002 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
8.6 |
Times cited |
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Open Access |
Not_Open_Access |
| Notes |
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Approved |
Most recent IF: 8.6 |
| Call Number |
UA @ admin @ c:irua:189086 |
Serial |
7084 |
| Permanent link to this record |
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| Author |
Milat, O.; Van Tendeloo, G.; Amelinckx, S.; Wright, A.J.; Greaves, C. |
| Title |
Effect of the substitution Ba\leftrightarrow Sr on the Ga-1222 superstructure : an electron diffraction study |
Type |
A1 Journal article |
| Year |
1995 |
Publication |
Chemistry of materials |
Abbreviated Journal |
Chem Mater |
| Volume |
7 |
Issue |
9 |
Pages |
1709-1715 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
| Abstract |
The superstructure of the RE(2)(Sr0.85-xBaxNd0.15)(2)GaCU2O9 compound is found to change significantly with increasing substitution of Ba for Sr. Most of the changes take place in the (Sr0.85-xBaxNd0.15)O-GaO-(Sr0.85-xBaxNd0.15)O lamella, the rest of the basic structure being hardly affected. The structural changes for O less than or equal to x less than or equal to 0.65 are studied by electron diffraction. The arrangement of the chains of GaO4 tetrahedra in the Ba-free compound becomes disordered at x > 0.25. At x similar to 0.65 a rearrangement of the chains in the GaO layers takes place; they form a meandering arrangement, which can be described on a 4a(p) x 2a(p) x c(p) superlattice. This rearrangement is accompanied by ordering of Ba and Sr atoms in the adjacent (ST0.85-xBaxNd0.15)O layers. A simple scheme is proposed to explain the influence of the substitution of Ba for Sr on the linking of the GaO4 tetrahedra and on the geometry of the ''chains'' in the GaO layer. |
| Address |
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Thesis |
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Place of Publication |
Washington, D.C. |
Editor |
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| Language |
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Wos |
A1995RW21200021 |
Publication Date |
2005-03-08 |
| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
0897-4756;1520-5002; |
ISBN |
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Additional Links |
UA library record; WoS full record |
| Impact Factor |
8.354 |
Times cited |
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Open Access |
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| Notes |
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Approved |
no |
| Call Number |
UA @ lucian @ c:irua:13326 |
Serial |
850 |
| Permanent link to this record |
