University of Pennsylvania

Dawn A Bonnell

Sergei V Kalinin

Rodolfo Antonio Alvarez

Alan T Johnson

Xiaojun Joseph Lei

David Conklin

Douglas Robert Strachan

Peter K Davies

Danvers E Johnston

Rui Shao

Beth S Guiton

Marcus Freitag

Disclosed are devices comprising multiple nanogaps having a separation of less than about 5 nm. Also disclosed are methods for fabricating these devices.

Parallel fabrication of nanogaps and devices thereof

Disclosed are electronic, plasmonic and opto-electronic components that are prepared using patterned photodeposited nanoparticles on a substrate surface. Also disclosed are ferroelectric nanolithography methods for preparing components, circuits and devices.

Electronic and optoelectronic devices having nanoparticles configured by patterned ferroelectric material

Scanning probe techniques based on the measurement of impedance spectroscopy using a conductive an SPM tip is provided and applied to the study of local transport properties, especially at a grain boundary. The contributions of the grain boundaries and tip-surface interaction can be distinguished based on the analysis of the equivalent circuit. The technique is applicable for both the spatially resolved study of transport mechanisms of polycrystalline semiconductors and the tip-surface contact quality. A piezoresponse force microscopy technique yields quantitative information about local non-linear dielectric properties and higher order electromechanical coupled of ferroelectrics.

Scanning probe microscopy apparatus and techniques

A method for determining a magnetic force profile of a sample by using a cantilevered probe having a magnetic tip, the method comprising the steps of: traversing the tip along a predetermined path on the surface of the sample, the tip being proximate the surface of the sample while traversing along the predetermined path; determining the sample surface topography along the path; substantially canceling the sample surface potential along the path using the determined sample surface topography; and determining magnetic force data along the path based on the determined surface topography, wherein the determined magnetic force data is not magnetic force gradient data and the determined magnetic force data includes substantially no components from the sample surface potential.

Spatially resolved electromagnetic property measurement

Electronic and optoelectronic devices and methods for preparing same

A ferroelectric substrate () is patterned using local electric fields from an apparatus () to produce nanometer sized domains with controlled surface charge (), that allow site selective metalization () and subsequent reaction with functional molecules (), resulting in nanometer-scale molecular devices.

Directed assembly of nanometer-scale molecular devices

A scanning probe detects phase changes of a cantilevered tip proximate to a sample, the oscillations of the cantilevered tip are induced by a lateral bias applied to the sample to quantify the local impedance of the interface normal to the surface of the sample. An ac voltage having a frequency is applied to the sample. The sample is placed at a fixed distance from the cantilevered tip and a phase angle of the cantilevered tip is measured. The position of the cantilevered tip is changed relative to the sample and another phase angle is measured. A phase shift of the deflection of the cantilevered tip is determined based on the phase angles. The impedance of the grain boundary, specifically interface capacitance and resistance, is calculated based on the phase shift and the frequency of the ac voltage. Magnetic properties are measured by applying a dc bias to the tip that cancels electrostatic forces, thereby providing direct measurement of magnetic forces.

The present invention is directed to a tip calibration standard for characterizing the geometric and electrostatic properties of the probe tips of scanning probe microscopes comprising a carbon nanotube mounted on a dielectric surface of a grounded, conductive substrate and connected to a contact mounted on the substrate. The present invention is also directed to methods for using such a tip calibration standard in calibrating probe tips, computing tip geometry and electrostatic data, and determining the convolution function so that tip-surface interaction effects can be separated from scanning probe microscope surface image data.

Growing community of inventors

West Chester, PA, United States of America

Dawn A Bonnell