Synthesis and characterization of semiconductor and semiconductor-metal nanoparticles [Elektronische Ressource] / Elena Selishcheva. Betreuer: Joanna Kolny-Olesiak
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Publié par
Publié le
01 janvier 2012
Nombre de lectures
16
Langue
English
Poids de l'ouvrage
8 Mo
Publié par
Publié le
01 janvier 2012
Nombre de lectures
16
Langue
English
Poids de l'ouvrage
8 Mo
Synthesis and Characterization of
Semiconductor and
Semiconductor-Metal
Nanoparticles
Von der Fakult at fur Mathematik und Naturwissenschaften der Carl von
Ossietzky Universit at Oldenburg zur Erlangung des Grades und Titels eines
Doctor rerum naturalium (Dr. rer. nat.)
angenommene Dissertation
von
Frau Elena Selishcheva
geboren am 4.2.1985 in Woronesch (Russland)Gutachter: Prof. Dr. Joanna Kolny-Olesiak
Zweitgutachter: Prof. Dr. Jurgen Parisi
Tag der Disputation: 19.12.2011
iiAbstract
Nanoparticles are promising materials for many physical and chemical ap-
plications, because their properties depend on their size and shape, which
can be controlled during the synthesis.
This work is a contribution to the development of colloidal synthesis of
di erent nanomaterials, such as lead chalcogenide PbE (E = S, Se, Te),
indium oxide (In O ) nanoparticles, and hybrid nanostructures, consisting2 3
of copper indium sul de selenide (CuInSSe) and gold nanoparticles.
After a short general introduction into the theory of synthesis of nanomate-
rials, the investigations of the three systems mentioned above are described.
In the rst part, nearly monodisperse PbE semiconductor nanoparticles pro-
duced via a novel synthesis which includes the occurrence of in situ formed
0Pb -particles are shown. Spherical PbSe nanoparticles are further investi-
gated with respect to possible application in hybrid solar cells.
The second part is about a novel non-injection synthesis route for the prepa-
ration of colloidal In O nanocrystals. The shape of the nanocrystals can2 3
be in uenced by the addition of copper ions.
Finally, the selective growth of gold nanocrystals onto CuInSSe nanoparti-
cles to form semiconductor/metal hybrid nanostructures is demonstrated.
The CuInSSe nanoparticles used in our experiments have a trigonal pyra-
midal shape. During the synthesis gold nanocrystals grow onto vertexes of
CuInSSe pyramids.
X-ray di raction, transmission electron microscopy, nuclear magnetic reso-
nance, UV-Vis absorption, photoluminescence and energy dispersive X-ray
spectroscopy are used to characterize the samples.ivKurzfassung
Nanopartikel sind ein vielversprechendes Material fur viele physikalische
und chemische Anwendungen, da ihre Eigenschaften von den Gr o en und
Formen abh angen, welche w ahrend der Synthese kontrollierbar sind.
Diese Arbeit ist ein Beitrag zur die Entwicklung der kolloidalen Synthese
von verschiedenen Nanomaterialien, wie Bleichalkogenide(PbE, E = S, Se,
Te)- und Indiumoxid(In O )-Nanopartikeln sowie hybriden Nanostrukturen,2 3
die aus Kupferindiumsul dselenid(CuInSSe)- und Gold-Nanopartikeln beste-
hen.
Nach einer kurzen allgemeinen Einleitung in die Theorie der Synthese von
Nanomaterialien werden die drei oben genannten Systeme beschrieben. In
dem ersten Teil werden quasi monodisperse PbE-Halbleiternanopartikel ge-
0zeigt, die mittels neuer Methode mit der Bildung von Pb -Partikeln syn-
thetisiert werden. Sph arische PbSe-Nanopartikel werden fur die Anwendung
in hybriden Solarzellen untersucht.
Der zweite Teil handelt von der neuen Synthese fur die Herstellung von
kolloidalen In O -Nanokristallen. Die Form der Nanokristalle konnte durch2 3
die Zugabe von Cu-Ionen beein usst werden.
Schlie lich wird das selektive Wachstum von Gold-Nanokristallen auf den
CuInSSe-Nanopartikeln mit der Bildung von hybriden Metall-Halbleiter-
Nanostrukturen dargestellt. Die CuInSSe-Nanopartikel haben eine pyra-
midale Form. W ahrend der Synthese wachsen Gold-Nanokristalle auf den
Spitzen dieser CuInSSe-Pyramiden.
Transmissionelektronenmikroskopie, UV-Vis Absorptions- und Photolumi-
neszenz-Spektroskopie, R ontgenbeugung, Energiedispersive R ontgenspek-
troskopie und Kernspinresonanzspektroskopie werden fur die Probencharak-
terisierung verwendet.viAcknowledgements
I would like to thank all my colleagues who contributed to this work, es-
pecially Jun.-Prof. Dr. Joanna Kolny-Olesiak for enabling me to accom-
plish my PhD; Prof. Dr. Jurgen Parisi for his support and agreement
to referee this thesis; Dr. Holger Borchert for good co-operations related
to PbSe NPs; Dr. Erhard Rhiel, Heike Oetting, and Renate Kort for assis-
tance in obtaining TEM images and EDX data, Andrea Tschirne and Dieter
Neemeyer for assistance in obtaining NMR data, Florian Witt and Niklas
Trautwein for ESR and PIA measurements, Dr. Daniela Fenske and Jo-
hannes Neumann for assistance in obtaining TGA data, Dr. Karsten Thiel
for assistance in obtaining HRTEM images, Kambulakwao Chakanga from
EWE-Forschungszentrum fur Energietechnologie e. V. for assistance in ob-
taining absorption spectra; Dr. Irina Lokteva for her help to start my work
here, Marta Kruszynska for synthesis of CuInS NPs used in this thesis, Dr.2
Xiaodong Wang, Dr. Jie Li, Xiaoping Jin, and Bj orn Kempken for a nice
collaboration, and Matthias Macke for the necessary chemicals. I am very
grateful to Florian for his help with LATEX and my family for support dur-
ing the past years. "EWE-Nachwuchsgruppe Dunnsc hicht Photovoltaik" by
the EWE AG, Oldenburg is acknowledged for nancial support.viiiContents
List of Figures xiii
Glossary xvii
1 Introduction 1
2 Theoretical background 5
2.1 Nanomaterials, their properties and application . . . . . . . . . . . . . . 5
2.1.1 Hybrid nanomaterials . . . . . . . . . . . . . . . . . . . . . . . . 13
2.2 Theory of nanocrystal synthesis . . . . . . . . . . . . . . . . . . . . . . . 15
2.2.1 Impact of experimental conditions . . . . . . . . . . . . . . . . . 15
2.2.2 Formation mechanism of spherical nanoparticles . . . . . . . . . 17
2.2.3 Shape control of nanoparticles . . . . . . . . . . . . . . . . . . . 24
2.2.4 Synthesis of hybrid nanostructures . . . . . . . . . . . . . . . . . 26
2.3 Characterization methods . . . . . . . . . . . . . . . . . . . . . . . . . . 27
2.3.1 Electron microscopy . . . . . . . . . . . . . . . . . . . . . . . . . 27
2.3.2 X-ray characterization methods . . . . . . . . . . . . . . . . . . . 29
2.3.3 Optical studies . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
2.3.4 Thermodynamic characterization methods . . . . . . . . . . . . . 32
3 Experimental part 35
3.1 Synthesis of lead chalcogenide nanocrystals . . . . . . . . . . . . . . . . 35
3.1.1 Hexylamine treatment of original PbSe nanocrystals . . . . . . . 37
3.2 Synthesis of indium oxide nanoparticles . . . . . . . . . . . . . . . . . . 37
3.2.1 Synthesis of ower-shaped In O nanocrystals . . . . . . . . . . . 382 3
3.2.2 Synthesis of In O nanocrystals employing organic ligand molecules 382 3
ixCONTENTS
3.2.3 Synthesis of quasi-spherical In O nanocrystals . . . . . . . . . . 382 3
3.2.4 Synthesis of elongated In O nanocrystals . . . . . . . . . . . . . 392 3
3.3 Synthesis of CIS and CIS/Au hybrid nanoparticles . . . . . . . . . . . . 39
3.3.1 Synthesis of CIS nanoparticles . . . . . . . . . . . . . . . . . . . 39
3.3.2 Synthesis of CIS/Au hybrid nanoparticles . . . . . . . . . . . . . 40
3.4 Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
3.5 Characterization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
4 Hot-injection synthesis of lead chalcogenide nanocrystals: In uence
of synthesis mechanism on the nanocrystal surface properties 45
4.1 Motivation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
4.2 Size and shape control of lead chalcogenide nanoparticles . . . . . . . . 47
4.3 Reaction mechanism and product characterisation . . . . . . . . . . . . 52
4.4 Surface investigation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
4.5 Study of charge transfer in blends of PbSe nanocrystals and P3HT . . . 60
4.6 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
5 Non-injection synthesis of In O nanoparticles and their shape control 652 3
5.1 Motivation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
5.2 Synthesis investigation and characterization of ower-shaped In O nanopar-2 3
ticles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
5.3 Shape control of In O nanoparticles using organic ligand molecules . . 712 3
5.4 Shape control of In O using copper ions . . . . . . . . . . 722 3
5.5 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77
6 Synthesis and characterization of CIS/Au hybrid nanoparticles 79
6.1 Motivation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
6.2 Synthesis and characterization of CuInSSe nanoparticles . . . . . . . . . 82
6.3 Synthesis and c of CuInSSe/Au hybrid nanostructures . . 85
6.4 CuInS /Au hybrid nanostructures: Di erence in the synthesis mechanism 892
6.5 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91
7 Summary 93
x
