FRINK Linked Data Fragments server

Matches in SemOpenAlex for { <https://semopenalex.org/work/W136366541> ?p ?o ?g. }

• W136366541 abstract "A detailed investigation and characterization of the local properties of individual nanoscopic structures is of great importance for the understanding of novel physical phenomena at the nanoscale as well as for the assessment of their possible use in future applications. A unique tool for the study of such structures are scanning probe methods. These methods do not only allow to obtain atomic scale information in both topographic and spectroscopic measurements at surfaces, but can also be employed for example to stimulate local photon emission. In this thesis the growth mechanism of inorganic and organic semiconductor nanostructures and the relation between their local structure and their electronic and optical properties is investigated by scanning probe techniques. In the first part of this thesis, the growth as well as the local electronic and morphologic properties of InAs/GaAs(001) quantum dots grown by molecular beam epitaxy are described. The recorded spectra show evidence of the discretization of the density of states that can be attributed to the zero dimensional confinement of charge carriers to the quantum dots. Moreover, the shape evolution of the quantum dots during the controlled removal of material through an in situ etching gas is studied. High resolution topographic images reveal that hereby an island shape transition takes place. This shape evolution is found to be the reverse of the shape evolution that typically takes place during the growth, indicating that thermodynamic factors play an important role during the growth process and the etching process. In addition, the mechanism of the material removal from the quantum dots is investigated in detail by the analysis of the size evolution of the islands as a function of the nominal amount of etched material. The second part of this thesis is dedicated to the study of individual CdSe nanowires grown by the solution-liquid-solid approach. These nanowires consist of small alternating sections of wurtzite and zincblende lattice structures. This structural arrangement also leads to an alternating electronic structure in the form of a type II band alignment along the long axis of the nanowires. The local electronic properties of the nanowires are analyzed by scanning tunneling spectroscopy. Tunneling current induced luminescence spectra from individual nanowires are acquired by the injection of holes and electrons and their subsequent radiative recombination. In contrast to previous studies on similar systems, the coupling of tip induced plasmons to the radiation process is not required. The shape and the position of the luminescence spectra is compared to photoluminescence spectra and Raman measurements. The photon energy is found to decrease with increasing wire diameter indicating quantum confinement of the charge carriers to the wire. The bulk bandgap, that can be extrapolated from the energy vs. diameter dependence of the emission peaks, indicates that the photons are emitted from zincblende type CdSe sections. Moreover, the diameter dependence reveals that the emission stems from carriers that are confined to quantum dot like parts of the wires. The lack of light emission from the wurtzite type segments is also re ected in the appearance of non-luminescent regions in the NW as shown by spatially resolved light intensity maps. Possible mechanisms for the light excitation are discussed. The investigation of single molecules of the luminescent organic emitter tris-(2-phenylpyridine)iridium(III) (Ir(ppy)3) is the topic of the last part of this thesis. To this end, Ir(ppy)3 molecules are deposited onto metal substrates and different types of thin insulating layers. Besides their structural and electronic characterization, the optical properties of single molecules are studied by tunneling current induced luminescence. No intrinsic light emission originating from the molecules can be observed neither on metal substrates nor on thin insulating layers. This indicates that in these systems, the molecules are still not sufficiently decoupled from the underlying metallic substrate. Preliminary results of tunneling current induced luminescence measurements of Ir(ppy)3 molecules on multilayers of C60 show great promise for exciting light emission on single molecules." @default.
• W136366541 created "2016-06-24" @default.
• W136366541 creator A5024388806 @default.
• W136366541 date "2011-01-01" @default.
• W136366541 modified "2023-09-23" @default.
• W136366541 title "Scanning Tunneling Microscopy and Luminescence of Individual Nanostructures" @default.
• W136366541 cites W1500154531 @default.
• W136366541 cites W1586668292 @default.
• W136366541 cites W1588671392 @default.
• W136366541 cites W1615700627 @default.
• W136366541 cites W1966282563 @default.
• W136366541 cites W1967311848 @default.
• W136366541 cites W1968050981 @default.
• W136366541 cites W1972262271 @default.
• W136366541 cites W1973696945 @default.
• W136366541 cites W1974830441 @default.
• W136366541 cites W1979448017 @default.
• W136366541 cites W1979527355 @default.
• W136366541 cites W1982762932 @default.
• W136366541 cites W1983739651 @default.
• W136366541 cites W1989034496 @default.
• W136366541 cites W1996077400 @default.
• W136366541 cites W1998711958 @default.
• W136366541 cites W1999115975 @default.
• W136366541 cites W1999997583 @default.
• W136366541 cites W2001992992 @default.
• W136366541 cites W2002771295 @default.
• W136366541 cites W2004124513 @default.
• W136366541 cites W2005884429 @default.
• W136366541 cites W2008695248 @default.
• W136366541 cites W2013789532 @default.
• W136366541 cites W2018015695 @default.
• W136366541 cites W2018477162 @default.
• W136366541 cites W2018794940 @default.
• W136366541 cites W2019200377 @default.
• W136366541 cites W2020538374 @default.
• W136366541 cites W2023579904 @default.
• W136366541 cites W2028276808 @default.
• W136366541 cites W2031606451 @default.
• W136366541 cites W2032206958 @default.
• W136366541 cites W2033787520 @default.
• W136366541 cites W2034151899 @default.
• W136366541 cites W2035167135 @default.
• W136366541 cites W2036959049 @default.
• W136366541 cites W2037587947 @default.
• W136366541 cites W2041575849 @default.
• W136366541 cites W2045866671 @default.
• W136366541 cites W2046032184 @default.
• W136366541 cites W2048861751 @default.
• W136366541 cites W2052725676 @default.
• W136366541 cites W2054625634 @default.
• W136366541 cites W2056474643 @default.
• W136366541 cites W2059588446 @default.
• W136366541 cites W2060441787 @default.
• W136366541 cites W2061000251 @default.
• W136366541 cites W2061340530 @default.
• W136366541 cites W2062021970 @default.
• W136366541 cites W2063294089 @default.
• W136366541 cites W2063468757 @default.
• W136366541 cites W2066131058 @default.
• W136366541 cites W2066411352 @default.
• W136366541 cites W2073792766 @default.
• W136366541 cites W2074475782 @default.
• W136366541 cites W2076047831 @default.
• W136366541 cites W2078475532 @default.
• W136366541 cites W2078586705 @default.
• W136366541 cites W2078833116 @default.
• W136366541 cites W2080408090 @default.
• W136366541 cites W2081150899 @default.
• W136366541 cites W2082087822 @default.
• W136366541 cites W2085511939 @default.
• W136366541 cites W2086262956 @default.
• W136366541 cites W2087064869 @default.
• W136366541 cites W2088211690 @default.
• W136366541 cites W2089977691 @default.
• W136366541 cites W2090867916 @default.
• W136366541 cites W2091951243 @default.
• W136366541 cites W2092617845 @default.
• W136366541 cites W2103282498 @default.
• W136366541 cites W2107609474 @default.
• W136366541 cites W2119691274 @default.
• W136366541 cites W2119832285 @default.
• W136366541 cites W2129279308 @default.
• W136366541 cites W2142224432 @default.
• W136366541 cites W2144429427 @default.
• W136366541 cites W2240929658 @default.
• W136366541 cites W2317970640 @default.
• W136366541 cites W2342275709 @default.
• W136366541 cites W2483424394 @default.
• W136366541 cites W2494197051 @default.
• W136366541 cites W293484733 @default.
• W136366541 cites W365385536 @default.
• W136366541 cites W561633959 @default.
• W136366541 cites W899046642 @default.
• W136366541 cites W2026219400 @default.
• W136366541 doi "https://doi.org/10.5075/epfl-thesis-4969" @default.
• W136366541 hasPublicationYear "2011" @default.
• W136366541 type Work @default.
• W136366541 sameAs 136366541 @default.
• W136366541 citedByCount "0" @default.

• next