The electronic structures at the hetero interface of Poly(3-hexylthiophene): methanofullerene (P3HT:PCBM) have a great improvement on the solar cell efficiency due to the formation of bicontinuous nanoscaled phase separation which will enhance charge separation and carrier transport. In the present work, cross-sectional scanning tunneling microscopy and scanning tunneling spectroscopy measurements are utilized to obtain the in-situ atomic-scale band structure across the interface between P3HT and PCBM directly. The distribution of PCBM volume concentration of organic films was also analyzed and discussed in the work.

The electronic structure at interface between two insulators LaAlO3 and SrTiO3 has been investigated by using scanning tunneling microscopy and spectroscopy. The atomic-scale interfacial band structure is also demonstrated in the work with the consideration of the tip-induced band bending effect. Experimental results indicate that the magnitude of the built-in field across LaAlO3 is 0.075¡Ó0.005 V/Å. The band bending on SrTiO3 side at the heterointerface is observed. The band downshift of SrTiO3 side at the interface is 0.1 eV with ~1 nm decay length.

In this work, the interfacial electronic property between N-type LaAlO3/TiO2-SrTiO3 has been investigated by using scanning tunneling microscopy and spectroscopy (STM/S). With the consideration of the tip-induced band bending effect during STM measurements and in conjunction with the three-dimensional theoretically analysis, the schematic band structure of the hetero-structured SrTiO3/LaAlO3 is also revealed. Results indicate that the magnitude of the built-in field on the LaAlO3 is (30¡Ó5) mV/Å. The band bending on SrTiO3 side at the heterointerface is also observed. The band downshift of SrTiO3 side at the interface is 0.31 eV with about 0.8 nm decay length.

To estimate the correct dimension of the target on the underwater, we can use CCD camera and cast laser light strip onto the target, and then observe the displacement of laser light to get the dimension. Since the laser light will show on different situation, it's due to the surface of the target is not smooth. When we get the image from CCD camera, we need to calibrate the displacement of the laser light and return to the actual dimension of the target on the underwater. We know the optical distortion and non-linearity of the CCD camera will influence to get the correct image, also the location of camera is. That's the reason we need to calibrate the camera first. It was a mathematical way to explain the calibration of CCD camera non-linearity before. On this subject, we lay vertical and horizontal grid lines of 50 mm span on an acrylic plate. These grid lines are same as the longitudes and latitudes of the map. We estimate the target with the pair of interpolated longitude and latitude same as to be used to estimate the location of the point in the world coordinate system. And choose some targets with different size and form to use to verify the approach. By the way, we also test if there is any influence for the clear of water. The results indicate the error is under 3 \% when we catch the image on the underwater by a calibrated CCD camera.

No description available.

A Pan-style scanning tunneling microscope (STM), with a vertical coarse approach mechanism, was designed, built and tested. The microscope will be operated in ultra-high vacuum and also at cryogenic temperatures (8 K) inside a continuous flow cryostat. Fundamental differences in operating principle exist between the new microscope and the beetle-type inertial sliders [1] that have been the mainstay of the group for the last eight years. While Pan-style microscopes do already exist [2], they remain challenging to build, and an active area of research [3]. This system represents a bold departure from well-trodden paths, and will greatly expand the range of experiments that our group can perform. The operating principles of inertial piezoelectric motors are detailed. Design guidelines for a piezoelectric motor are given, and used in the design of the vertical coarse approach motor. A simple, inexpensive implementation for creating waveforms with an extremely fast fall time is discussed. Motor performance is tested, and a minimum step size of 20nm is found for frequencies ranging from 0 Hz to 3 kHz. The motor operates with high dynamic range: individual 20nm steps can be taken, as well as being able to move at a velocity of 0.4mm s−1. Little is known about the vibrational properties of Pan-style microscopes. Vibrational testing of the microscope revealed the expected scanner bending mode at 1.6 kHz (above the scanner bending mode of our beetles at 1.2 kHz), and a complicated response signal above this frequency. Custom extension springs for an eddy-current damping system are built and tested. A low resonant frequency of 1.8 Hz is found, which is ideal for the application. Initial testing of the STM in ambient conditions is performed on two different surfaces. A moir´e supermesh [4] with periodicity 3nm is observed on a highly-oriented pyrolytic graphite (HOPG) surface, and agrees well with previously published results. Using a flame-annealed Gold on mica surface, a low drift rate of 0.6nm s−1 is observed over a period of 13 minutes. Single-height atomic steps are observed on both surfaces. Additionally, the microscope is shown to be capable of zooming into different features on a surface, and scanning at different length scales. / Thesis (Master, Physics, Engineering Physics and Astronomy) -- Queen's University, 2009-06-24 13:06:16.683

Aim: To use the extraoral scanner 3D Sense in practice and compare the measurements on scanned material with conventional, direct clinical measurements. This is to evaluate if extraoral scanning can replace a clinical examination and extraoral 2D photography. Material & method: Fifteen adults at the Faculty of Odontology were recruited for the study. Five determined landmarks were marked in the faces of the subjects. Direct clinical measurements were performed between the landmarks of every subject and used as a reference. The subjects' faces were scanned and the same distances were measured in the scans. Differences in measurements of the two methods were conducted in a paired t-test. Intra- and inter operator differences were calculated for all distances. Intraclass correlations were used to describe to what extent subjects in the same group resemble each other.  Results: Conformity of direct clinical measurements and measurements on scanned material varied between the mean difference of 0,22-5,13 mm. Intra- and inter operator ICC was overall excellent. Conclusion: The measurements between the landmarks pronasale (prn) and pogonion (pg) was the only distance with no statistical significant difference between the two methods. The 3D Sense shows decreasing conformity to clinical measurements with increasing distances. Inter operator ICC shows excellent values and measuring on scanned material can be regarded as a reproducible method. The results indicate clinical acceptance for use of 3D Sense for some purposes in odontology. 3D Sense has been validated in-vitro and analyzed in-vivo. The studies have established the 3D Sense’s adequacy in odontology.

A scanning force microscope is an instrument which can image the forces present on a sample with high resolution. These forces include magnetic, electric, and atomic forces. The scanning force microscope uses either a tunneling, capacitive or optical method of sensing the motion of a lever-tip mechanical system that reacts to the forces present on a sample. There are four optical methods used in scanning force microscopy: heterodyne, homodyne, deflection and laser feedback. In this thesis, two implementations of the laser feedback method of detecting lever motion are described: a fiber coupled laser diode feedback and a tightly coupled laser diode feedback. The theory of interactions between a tip and the magnetic or electric fields at the surface of a sample are presented, along with the theory of the laser diode feedback. The limiting noises inherent in the system are discussed and representative values are given. Results of the sensitivity of the two systems are presented, and images of electric forces acting on the tip from interdigitated electrodes are demonstrated.

No description available.

No description available.