electrical characterization of self assembled monolayers

... control over the shapes of nanowire bundles and nanorods, allowing the formation of urchin-like crystalline h-WO3 via simple substitution of NH4 + in place of Na+ ions of EDTA salt solutions Experimental ... 2b that the self- assembled nanowires formed nanowire bundles as a result of the synthesis approach using Na+ -based EDTA salt solution Alternatively, numerous nanorods were self- assembled to ... addition of NH4 + -based EDTA in place of Na+ -based EDTA, while the other conditions were maintained the same Highly oriented 1D nanowires were self- assembled to form nanowire bundles of h-WO3...

Ngày tải lên: 19/03/2014, 16:48

... concept of the self- assembled monolayers (SAMs) is primarily introduced by Zisman in 1946 [12, 13] The traditional SAMs is an organized layer of INTRODUCTION amphiphilic molecules in which one end of ... on top of carbon atoms of the second layer, whereas the carbon atoms in black are located above the center of the six-fold carbon rings of the second layer [4] Fig 1.1 Crystal structure of HOPG ... typical example is that the formation of thiolate monolayers on the gold (111) surface (Fig 1.3) Fig 1.3 Schematic of an n-dodecanethiolate monolayer self- assembled on an atomically flat gold...

Ngày tải lên: 14/09/2015, 08:37

... automatic cutoff circuit is used to cut off the potential to avoid over-etching The cutoff time of the etching has a significant effect on the radius of curvature of the tip: the faster the cutoff time, ... The direction of the electron flow depends on the sign of the applied bias on the sample For a positive bias, electrons flow from occupied states of the tip to unoccupied states of the sample ... 2, 4] 2.1.3 Preparation of the STM Tips The reliable fabrication of tunneling probe tips is critical for the proper operation of STM The size, shape and chemical identity of the tip influence not...

Ngày tải lên: 14/09/2015, 08:37

... and detection of sound, generation of high voltages, electronic frequency generation, microbalance, and ultra fine focusing of optical assemblies It is also the basis of operation of the scanning ... prior to calibration (6×6 nm, Vbias=80mV, Ioffset=30pA) Image was treated with Lowpass function of the Nanoscope IIIa software to remove noise The alignment of the graphite crystal on the working ... STM images of HOPG were captured again after scanning for a certain period of time when whole work station became stable Fig 3.6 Calibration parameters of scanner A The new value of spacing between...

Ngày tải lên: 14/09/2015, 08:37

... structure of the underlying graphite surface lattice The image of heneicosanoic acid monolayers and image of HOPG were put in same picture In Fig 4.3 the upper quarter is the STM image of the graphite ... PHYSISORPTION OF BINARY FATTY ACIDS ON HOPG formed by binary mixture of CH3(CH2)19COOH and CH3(CH2)22COOH with weight ratio of 2:1 is shown in Fig 4.6 Fig 4.6 STM image of a monolayer formed of heneicosanoic ... observed in monolayers High resolution STM studies are necessary to identify the molecular structures of the SAMs The high resolution STM images of the monolayers at different locations of the same...

Ngày tải lên: 14/09/2015, 08:37

... height of 0.2 nm (Fig 5.3) Fig 5.3 The height profile of the DDPER Self- Assembled Monolayers 78 FORMATION OF SAMs CONRTOLLED BY STERIC EFFECTS In conclusion, the DDPER molecules form stable self- assembled ... orientate along the diagonal direction of the unit cell 77 FORMATION OF SAMs CONRTOLLED BY STERIC EFFECTS Fig 5.2 The enlarged STM results of the Self- Assembled Monolayers formed by DDPER from saturated ... size of the side groups can affect the formation of the monolayers at the liquid/HOPG interface By varying the size of the attached side groups, we may be able to control the stability of the monolayers...

Ngày tải lên: 14/09/2015, 08:37

... STM image of two types of SAMs arrangement and their boundary Bottom: The surface plot of the STM image (current profile) The height of each pinnacle is proportional to the magnitude of current ... ADSORPTION-INDUCED CHIRAL SAMs away from the monolayers The presence of rectangular unit cell of the monolayers indicated that the structure and symmetry of the monolayers are mainly determined by the ... HOPG The existence of phase separated chiral monolayers also indicated the physisorbed monolayers were the thermodynamically stable products of self- assembly process Formation of desired chiral...

Ngày tải lên: 14/09/2015, 08:37

... Proposed process of formation of the 2D crystals The theory of growth of perfect crystals has been well developed For the growth of a three dimensional crystal, it mainly occurs at steps of monomolecular ... equilibrium constant of reaction (7-3) 7.4.2 The surface structure of HOPG and [N] [N] is the density of the kinks on the step of the graphite crystal surface which is the nature of the graphite crystal ... example is the organic monolayers on the HOPG, which will be discussed further in this chapter As a unique tool in the study of the physisorbed organic monolayers, the use of scanning tunneling...

Ngày tải lên: 14/09/2015, 08:37

... NPs at doses of 0.5, 1.0, 4.0, and 11 nC/cm versus the v/v% ratio of MPTS/ OTS binary mixture The error bars represent the standard errors of the mean of the NNDs Fig SEM images of FIB nanolithography ... was the highest The lateral sizes of Au NPs were constant at diameters of *24 nm At lower doses Fig SEM images of FIB nanolithography aligned Au NPs at a dose of 0.5 nC/cm refilled with (a) 20 ... Consortium (OPC), and CRC Program of the Government of Canada for their kind financial support and the Western Nanofabrication Facility for the availability of FIB and SEM We also thank Todd Simpson...

Ngày tải lên: 22/06/2014, 00:20

... representation of the experiments Glass surfaces were modified with self- assembled monolayers of FPS, APS, OTC, and CMS; these were then put into one petri dish After one day of incubation, some of the ... knowledge has not been applied to the development of biodevices involving the use of diatoms On the other hand, self- assembled monolayers (SAMs) are one of the most useful techniques used in nanotechnology ... Coleman SE, Nolasco AC, Lopez GP: Use of self- assembled monolayers of different wettabilities to study surface selection and primary adhesion processes of green algal (Enteromorpha) zoospores...

Ngày tải lên: 11/08/2014, 00:22

... adsorptions of L-tartaric acid on gemini-type self assembled monolayers, and the change in work functions of a gold substrate modified by self assembled azobenzene derivatives 1.1 Introduction to Self Assembled Monolayers ... Introduction 1.1 Self- Assembled Monolayers Figure 1.1.2 Evolution of adsorption of mercaptohexanol on Au(111) From Poirier et al Ref 5    Chapter 1: Introduction 1.1 Self- Assembled Monolayers     ... Self- Assembled Monolayers The ends of alkane thiols can further be functionalized with moieties of interest to prepare functionalized self- assembled monolayers The ability of the alkane thiols to self- assemble...

Ngày tải lên: 11/09/2015, 09:11

... GOD, point of light, SHIVA vi Table of Contents Table of Contents Page Number Preamble i Acknowledgements v Table of Contents vii Summary xiv List of Tables xvi List of Figures xvii List of Notations ... wear durability data of L-B films, SAMs and polymer films 31 viii Table of Contents 2.5.1 Langmuir-Blodgett monolayers (L-B monolayers) 31 2.5.2 Alkyl-based Self- Assembled monolayers (SAMs) 32 ... Satyanarayana and S K Sinha, “Tribology of PFPE overcoated self- assembled monolayers deposited on Si surface”, Journal of Physics D: Applied Physics 38 (2005) 3512-3522 (a part of Chapter 4) 2) N Satyanarayana,...

Ngày tải lên: 14/09/2015, 12:11

... show that the surface of the particles is fully covered with selfassembled SiNWs A careful examination of the image at still higher magni®cation (Fig 3d) shows Fig (a) Self- assembled SiNWs are ... top surface of the cone is rather rough Fig 4c is the SEM image of the mushroom-shaped particles at still higher magni®cation, which shows clearly that the surface is full of self- assembled SiNWs ... morphological sensitivity of SiNWs to the growth temperature and composition, many types of SiNWs can be formed, rendering the determination of the growth mechanism of SiNWs more dicult Fig...

Ngày tải lên: 16/03/2014, 15:06

... 266 nm) quality of self- assembled ZnO 3D nanostructure were obtained at pH 10.5 This study was supported by the ERC (Center for Materials and Processes of Self- Assembly) program of MOST/KOSEF (R112005-048-00000-0) ... values of TC (1 0), TC (1 1) and TC (0 2) Fig shows the FE-SEM images of the self- assembled ZnO 3D nanostructures, which were synthesized in an aqueous solution at various pH The shape of the ... quality of self- assembled ZnO 3D nanostructure were obtained at pH 10.5 Acknowledgments Fig Room-temperature photoluminescence spectra from the ZnO 3D nanostructures grown in solutions of different...

Ngày tải lên: 06/05/2014, 13:24

... surface; number of electrical charges ix Introduction Self- assembly of chemical structures has attracted a great interest throughout the history of nanotechnology Good examples of self- assembled systems ... properties of a self- assembled monolayer built on Au(111) surface The second approach (publication V) presents a study of lateral conductivity of a film consisting of gold nanoclusters The uniqueness of ... properties of a single molecule For electrochemists, spontaneous formation of self- assembled monolayers [100, 101] of thiol-terminated molecules on Au(111) surface provides a way for the measurement of...

Ngày tải lên: 04/06/2014, 15:05

... conductivity of aqueous suspensions of carbon nanotubes (carbon nanotubes nanofluids) J Thermophys Heat Transfer 2004, 18:481-485 Hong T, Yang H, Choi CJ: Study of the enhanced thermal conductivity of ... Mechanisms of thermal nanofluids on enhanced critical heat flux (CHF) Int J Heat Mass Transfer 2008, 51:4958-4965 20 Zhou SQ, Ni R: Measurement of the specific heat capacity of water-based Al2O3 nanofluid ... conductivity of nanofluids J Appl Phys 2004, 95:6492-6494 27 Prasher R, Phelan PE, Bhattacharya P: Effect of aggregation kinetics on the thermal conductivity of nanoscale colloidal solutions (nanofluid)...

Ngày tải lên: 21/06/2014, 04:20

... voltage with a peak-to-peak amplitude of 200 mV served as an ac modulation source Various values of reverse dc bias voltage Ub was employed The modulation reflectance of the samples was filtered with ... (Figure 2) The spectral response of the device with QDs clearly covers a broader spectral range extending down to a half of eV Figure 3a shows typical results of ER spectroscopy We did not observe ... values of the energies are represented by bars in the figure Yakimov et al Nanoscale Research Letters 2011, 6:208 http://www.nanoscalereslett.com/content/6/1/208 Page of for the reverse bias of...

Ngày tải lên: 21/06/2014, 05:20

... dependence of the X and XX peaks of the shallow-hole QD of Fig 2a Lines: fits with slope = for the X and slope = for the XX peaks b Position of the X peak maximum of the shallow-hole QD of Fig 2a ... 180 [degree] EX- EXX [meV] XX an exciton FSS of 22 leV and a bieciton splitting of 28 leV These data demonstrate the state of the art optical quality of LDE GaAs QDs being comparable to the established ... biexciton peaks were identified on basis of their excitation power dependence (Fig 3a), with slope of one for X and of two for XX Polarization-dependent measurements of the neutral exciton and biexciton...

Ngày tải lên: 21/06/2014, 17:20

... fabrication of a novel type of very uniform, strain-free GaAs QDs by filling of LDE nanoholes in AlGaAs with GaAs, has been demonstrated [21] In the present paper we describe the influence of the LDE ... (peak P1 in Fig 5a) of around 1.65 eV with data shown in Ref [21], we estimate a QD height of about nm The excited-state peak P2 has a quantization energy of 20 meV and peak P3 of 42 meV According ... considering a similar type of QDs in Ref [30] Conclusions The local droplet etching of nanoholes in semiconductor surfaces represents a powerful new degree of freedom for the design of novel semiconductor...

Ngày tải lên: 22/06/2014, 00:20

... positioning of self- assembled QDs on patterned substrates Nanoscale Res Lett (2006) 1:1–10 surface of larger QDs The detailed shape of such QDs has been revealed by a facet analysis of STM data ... to fabricate lateral QD-molecules, based on the use of hierarchical self- assembly In hierarchically selfassembled structures the result of a self- assembly step is used as the starting point for ... based on the self- assembled InAs/GaAs QD system The route starts with the shape of freestanding QDs, followed by the homogeneity of buried QDs The local QD positioning and the fabrication of short-range...

Ngày tải lên: 22/06/2014, 22:20