Current-voltage Characteristics of Single CdSe Colloidal Nanodots Measured by Conductive-tip Atomic Force Microscopy

2002 ◽  
Vol 737 ◽  
Author(s):  
Ichiro Tanaka ◽  
Eri Kawasaki ◽  
O. Ohtsuki ◽  
K. Uno ◽  
M. Hara ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Room Temperature ◽  
Sample Surface ◽  
Self Assembled Monolayer ◽  
Contact Mode ◽  
Force Microscopy ◽  
Atomic Force ◽  
Current Voltage ◽  
Current Voltage Characteristics ◽  
Being Moved

ABSTRACTWe have investigated current-voltage characteristics of individual CdSe colloidal nanodots by conductive-tip atomic force microscopy (AFM). The colloidal nanodots were spun-coat and scattered on a self-assembled monolayer of thiophene molecules formed on Au (111) surfaces for single dot measurements. A thin SiO2 layer was deposited on the sample surface in order to prevent the dots being moved by the tip during measurement. We imaged the topography of isolated single dots by AFM operated in contact mode, and measured current-voltage characteristics with the conductive tip positioned on single dots; large conductivity changes which suggest resonant tunneling through a quantized energy level in the dot was observed even at room temperature.

scholarly journals A Non-Destructive, Tuneable Method to Isolate Live Cells for High-Speed AFM Analysis

2021 ◽  
Vol 9 (4) ◽  
pp. 680
Author(s):  
Christopher T. Evans ◽  
Sara J. Baldock ◽  
John G. Hardy ◽  
Oliver Payton ◽  
Loren Picco ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
High Resolution ◽  
High Speed ◽  
Single Cells ◽  
Sample Surface ◽  
Live Cells ◽  
Contact Mode ◽  
Force Microscopy ◽  
Atomic Force ◽  
Afm Analysis

Suitable immobilisation of microorganisms and single cells is key for high-resolution topographical imaging and study of mechanical properties with atomic force microscopy (AFM) under physiologically relevant conditions. Sample preparation techniques must be able to withstand the forces exerted by the Z range-limited cantilever tip, and not negatively affect the sample surface for data acquisition. Here, we describe an inherently flexible methodology, utilising the high-resolution three-dimensional based printing technique of multiphoton polymerisation to rapidly generate bespoke arrays for cellular AFM analysis. As an example, we present data collected from live Emiliania huxleyi cells, unicellular microalgae, imaged by contact mode High-Speed Atomic Force Microscopy (HS-AFM), including one cell that was imaged continuously for over 90 min.

Current Images of CdSe Colloidal Nanodots Observed by Conductive-tip Atomic Force Microscopy

2001 ◽  
Vol 692 ◽  
Author(s):  
Ichiro Tanaka ◽  
Eri Kawasaki ◽  
O. Ohtsuki ◽  
M. Hara ◽  
H. Asami ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Electronic Properties ◽  
Etch Pits ◽  
Self Assembled Monolayer ◽  
Contact Mode ◽  
Current Image ◽  
Single Crystalline ◽  
Force Microscopy ◽  
Atomic Force ◽  
Tunneling Resistance

AbstractWe have fabricated submonolayer-thick films of CdSe colloidal nanodots in order to investigate electronic properties of individual nanodots by conductive-tip atomic force microscopy (AFM). Topographic and current images of isolated single CdSe colloidal dots on single crystalline Au (111) surface which was covered with dodecanethiol self-assembled monolayer were obtained by AFM operating in contact mode with a conductive tip under appropriate bias voltages. In the current image, it is found that the dot regions have higher electric resistances due to tunneling resistance through the CdSe dots. We also found 10 nm-scale electric inhomogeneity around the dots, which may corresponds to the previously reported etch-pits of Au (111) surfaces formed during the deposition of the dodecanethiol molecules.

Atomic force microscopy study of small-size nanotubular polymer thin films

1999 ◽  
Vol 14 (3) ◽  
pp. 1084-1090 ◽  
Author(s):  
C. F. Zhu ◽  
I. Lee ◽  
J. W. Li ◽  
C. Wang ◽  
X. Y. Cao ◽  
...  
Keyword(s):  
Thin Films ◽  
Molecular Dynamics ◽  
Atomic Force Microscopy ◽  
Room Temperature ◽  
Polymer Thin Films ◽  
Microscopy Study ◽  
Atomic Force Microscopy Study ◽  
Contact Mode ◽  
Force Microscopy ◽  
Atomic Force

In this paper, we report atomic force microscopy (AFM) images of a tubular polymer and its supermolecular polymer thin films, operated in contact mode at room temperature in air. The configuration models are also calculated using molecular dynamics. The diameter of the polymer nanotube is about 0.7 nm, the smallest size a tube can have. The results of calculation agree with the experimental results.

Atomic Force Microscopy of the Local Electrical Properties of Bilayer Polyaniline-Polystyrene/P(VDF-TrFE) Composite

2021 ◽  
Vol 899 ◽  
pp. 506-511
Author(s):  
Artem V. Budaev ◽  
Ivanna N. Melnikovich ◽  
Vasily E. Melnichenko ◽  
Nikita A. Emelianov
Keyword(s):  
Atomic Force Microscopy ◽  
Electrical Properties ◽  
Polymer Nanocomposite ◽  
Charge Carriers ◽  
Force Microscopy ◽  
Atomic Force ◽  
Current Voltage ◽  
Current Voltage Characteristics ◽  
Piezoelectric Force Microscopy ◽  
Microscopy Techniques

Atomic force microscopy techniques (conductive-AFM, I-V spectroscopy and PFM) were used for characterisation of the local electrical properties of bilayer polyaniline-polystyrene/P(VDF-TrFE) polymer nanocomposite. Observed hysteresis of current-voltage characteristics confirms its memristive properties. It was caused by the influence of the ferroelectric polarization of P(VDF-TrFE) layer, the domain structure of which was visualised by piezoelectric force microscopy on the transport of charge carriers at the interface.

scholarly journals Study of the charge transfer process in the polyaniline/graphite heterojunction by conductive atomic force microscopy

2020 ◽  
pp. 94-98
Author(s):  
N. A. Davletkildeev ◽  
Keyword(s):  
Atomic Force Microscopy ◽  
Oxidative Polymerization ◽  
Pyrolytic Graphite ◽  
Thin Layers ◽  
Conductive Atomic Force Microscopy ◽  
Force Microscopy ◽  
Atomic Force ◽  
Current Voltage ◽  
Current Voltage Characteristics

Thin layers of polyaniline on the surface of highly oriented pyrolytic graphite are obtained by in-situ chemical oxidative polymerization of aniline. The current-voltage characteristics of the tip/polyaniline/graphite contact, which have a form characteristic of tunnel contacts, have been measured by the method of conducting atomic force microscopy. By modeling the current-voltage characteristics using the Simmons model, the width of the potential barrier is determined, which for the investigated heterojunction is 0,5 nm

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