Imaging of single quantum emitters using azimuthally and radially polarized laser beams [Elektronische Ressource] / vorgelegt von Anna Chizhik

Imaging of Single Quantum Emitters Using
Azimuthally and Radially Polarized Laser Beams







Dissertation
der Mathematisch-Naturwissenschaftlichen Fakultät
der Eberhard Karls Universität Tübingen
zur Erlangung des Grades eines
Doktors der Naturwissenschaften
(Dr. rer. nat.)






vorgelegt von
Dipl.-Phys. Anna Chizhik
aus Sankt Petersburg



Tübingen
2010


























Tag der mündlichen Qualifikation: 15.12.2010
Dekan: Prof. Dr. Wolfgang Rosenstiel
1. Berichterstatter: Prof. Dr. Alfred J. Meixner
2. Berichterstatter: Prof. Dr. Michael Hanack
1Contents

1 Introduction 5
1.1 Aim of this Thesis…………………………………………………………………...5
1.2 Scope of this Thesis…………………………………………………………………7

2 Instrumentation and Higher-Order Laser Modes 9
2.1 Instrumentation…………………………………………………………………….10
2.2 Higher-Order Laser Modes: Azimuthally and Radially Polarized Laser Beams......12
2.3 Imaging of Single Quantum Emitters Using Linearly Polarized Laser Beam……..17
2.4 Imaging of Fluorescence Spheres Using Higher-Order Laser Modes......................19
2.5 Imaging of Single Molecules Using Higher-Order Laser Modes….........................20
2.6 Summary and Conclusion……………………………………………………….....23

3 Imaging of the Excited-State Tautomerization in Single Metal-Free
Phthalocyanine and Porphyrin Molecules 24
3.1 Introduction………………………………………………………………………...25
3.2 Experimental……………………………………………………………………….27
3.3 NH Tautomerization……………………………………………………………….28
3.4 Simulated Excitation Patterns for Different Angles between Two Dipoles and
Different Orientation of the Molecule………………………………………………....29
3.5 Imaging of the Tautomerism Process in Single Phthalocyanine Molecules Using
Higher-Order Laser Modes ……………………………………………………………32
3.6 Imerism Process in Single Porphyrin Molecules Using an
Azimuthally Polarized Laser Beam.…………………………………………………...34
3.7 Summary and Conclusion………………………………………………………….37

4 Imaging of Single CdSe/ZnS Quantum Dots 39
4.1 Introduction………………………………………………………………………...40
4.2 Experimental……………………………………………………………………….41
24.3 Fluorescence Imaging of Single CdSe/ZnS Quantum Dotes Using Higher-Order
Laser Modes……………………………………………………………………………42
4.4 Blinking and Bleaching Behavior of Single CdSe/ZnS Quantum Dots…………...45
4.5 Summery and Conclusion……………………………………………………….…46

5 Imaging of Defect Luminescence in Single SiO Nanoparticles 47 2
5.1 Introduction………………………………………………………………………..48
5.2 Experimental……………………………………………………………………….49
5.3 3D Transition Dipole Moment Orientation of Single SiO Nanoparticles………...50 2
5.4 Emission Polarization of Single SiO Nanoparticles………………………………51 2
5.5 Blinking and Bleaching Behavior of Single SiO Nanoparticles…………………..53 2
5.6 Flipping of the Transition Dipole Moment Orientation in Single SiO 2
Nanoparticles…………………………………………………………………………..53
5.7 Summary and Conclusion………………………………………………………….55

6 Luminescence Imaging of Individual Si Nanocrystals. Part I: Defect
Photoluminescence 56
6.1 Introduction………………………………………………………………………...57
6.2 Experimental……………………………………………………………………….58
6.3 Fluorescence Imaging of Single Si NCs Using Higher-Order Laser Modes………61
6.4 Flipping of the Transition Dipole Moment Orientation in Single Si
Nanocrystals……….…………………………………………………………………...63
6.5 Summary and Conclusion………………………………………………………….64

7 Luminescence Imaging of Individual Si Nanocrystals. Part II: Exciton
Photoluminescence 66
7.1 Introduction………………………………………………………………………...67
7.2 Experimental……………………………………………………………………….68
7.3 Fluorescence Imaging of Single Si Nanocrystals Using an Azimuthally Polarized
Laser Beam…………………………………………………………………………….69
7.4 Summary and Conclusion………………………………………………………….71
38 Investigation of the Single Stopcock Molecules Orientation at Channel Entrances
of an Organic Host-Guest Compound 72
8.1 Introduction…………………………………………………………………….......73
8.2 Experimental……………………………………………………………………….74
8.3 Density Functional Theory Calculations…………………………………………..75
8.4 Single Stopcock Molecules in the Glass-Air Confinement………………………..76
8.5 PHTP – Crystals without Stopcock Molecules…………………………………….76
8.6 PHTP – Crystals with Stopcock Molecules………………………………………..77
8.7 Distribution of the Stopcock Molecules in the Channels…………………………..79
8.8 PHTP – Crystals with Single Stopcock Molecules………………………………...81
8.9 Crystals Oriented Vertically with Respect to the Sample Surface………………...82
8.10 Summary and Conclusion………………………………………………………...84

9 Investigation of the Single CdSe/ZnS Quantum Dots Orientation in the Channels
of Porous Silica Beads 85
9.1 Introduction………………………………………………………………………...86
9.2 Experimental……………………………………………………………………….86
9.3 Single Quantum Dots in the Glass-Air Confinement……………………………...88
9.4 Porous Silica Beads without and with Quantum Dots in the Channels……………89
9.5 Porous Silica Beads with Single Quantum Dots in the Channels………………….90
9.6 Distribution of the Quantum Dots in the Channels………………………………...91
9.7 Summary and Conclusion………………………………………………………….92

List of the Abbreviations 93

References 94

A Acknowledgement 102
B Abstract 104
C Zusammenfassung 106
41 Introduction
1.1 Aim of this Thesis
The combination of confocal microscopy with cylindrical vector beams (CVB)
(azimuthally and radially polarized laser beams) is widely used for the investigation of
the single quantum emitters. This method provides information about the excitation
transition dipole moment (TDM), while other microscopy techniques, e. g. defocusing
imaging [1, 2] or polarization microscopy [3], provide information about the emission
TDM. It has proven to be very efficient in probing the three-dimensional orientation and
dimensionality of excitation TDM of single molecules [4-6], Nile Red nano-spheres [7-
9], SiO nanoparticles [10, 11], gold nanoparticles [12] and gold cones [13]. 2
By comparing experimental and simulated excitation patterns of the single dye
molecules excited with an azimuthally or radially polarized laser beam (APLB and
RPLB, respectively) one can determine the two dimensional (2D) or three dimensional
(3D) excitation TDM orientation, respectively [4]. This information is important for such
applications, as Förster resonance energy transfer (FRET), since the efficiency not only
depends on the distance between donor and acceptor molecules, but also on relative
orientations of the two molecules.
The CVB technique has been applied for imaging of the excited-state tautomerism
process in single porphycene molecules [14, 15]. Single molecule excitation patterns
exhibit the reorientation of the TDM during the tautomerization and give the information
about 3D orientation of the molecules with respect to the sample surface, the angle
between the two TDMs of the molecule upon the tautomerism process and frequency of
the TDM reorientation, which can strongly vary for different types of the molecules.
Furthermore, it has been shown that the CVB can be used not only for
investigation of the emitter in free space, but also inside a tunable optical microresonator.
By analyzing the excitation patterns, resulting from the illumination with a RPLB, the
longitudinal position of the fluorescent Nile Red nano-beads or 3D orientation of the
single molecules inside the tunable microresonator can be determined [6, 8].
Recently it has been shown that this method can be also used for scattering
imaging of different shape single Au nanoparticles (spheres, rods, triangles) [12, 16]. The
5scattering images of the single Au nanoparticles excited with CVB provide an
information about the particles position, orientation, size and shape.
In this study we investigate photo-physical and photo-chemical propert