Night vision and thermal images are extensively used in military operations, as they help in mission planning and executions tasks. Image fusion effectively combines information present in each type of image. This research explored two wavelet-based image fusion approaches for night vision and thermal images; namely wavelet transform fusion and region-based fusion. Morphological methods designed to improve the image segmentation step were considered to improve image contrast and a global image quality index was applied to investigate the information content improvement resulting form the fusion process. Finally, a MATLAB-based graphical user interface was designed to assist the user in evaluating the benefits of the fusion process. Results showed the selection process is able to narrow to the best fused image with a satisfactory accuracy.

Thesis--PlanB (M.S.)--University of Wisconsin--Stout, 2003. / Includes bibliographical references.

Thesis--PlanB (Ed. Spec.)--University of Wisconsin--Stout, 2002. / Includes bibliographical references.

<p>Electrically active point defects in semiconductor materials are important because they strongly affect material properties like effective doping concentration and charge carrier lifetimes. This thesis presents results on point defects introduced by ion implantation in silicon and silicon carbide. The defects have mainly been studied by deep level transient spectroscopy (DLTS) which is a quantitative, electrical characterization method highly suitable for point defect studies. The method is based on measurements of capacitance transients and both standard DLTS and new applications of the technique have been used.</p><p>In silicon, a fundamental understanding of diffusion phenomena, like room-temperature migration of point defects and transient enhanced diffusion (TED), is still incomplete. This thesis presents new results which brings this understanding a step closer. In the implantation-based experimental method used to measure point defect migration at room temperature, it has been difficult to separate the effects of defect migration and ion channeling. For various reasons, the effect of channeling has so far been disregarded in this type of experiments. Here, a very simple method to assess the amount of channeling is presented, and it is shown that channeling dominates in our experiments. It is therefore recommended that this simple test for channeling is included in all such experiments. This thesis also contains a detailed experimental study on the defect distributions of vacancy and interstitial related damage in ion implanted silicon. Experiments show that interstitial related damage is positioned deeper (0.4 um or more) than vacancy related damage. A physical model to explain this is presented. This study is important to the future modeling of transient enhanced diffusion.</p><p>Furthermore, the point defect evolution in low-fluence implanted 4H-SiC is investigated, and a large number of new defect levels has been observed. Many of these levels change or anneal out at temperatures below 300 C, which is not in accordance with the general belief that point defect diffusion in SiC requires high temperatures. This thesis also includes an extensive study on a metastable defect which we have observed for the first time and labeled the M-center. The defect is characterized with respect to DLTS signatures, reconfiguration barriers, kinetics and temperature interval for annealing, carrier capture cross sections, and charge state identification. A detailed configuration diagram for the M-center is presented.</p>

Thesis (M.S.E.E.)--University of Puerto Rico, Mayagüez Campus, 2004. / Printout. Tables. Includes bibliographical references (leaves 122-124).

Further, a highly selective dry etch process for etching Al on AlN has been developed for the fabrication of MIM, MIS, SAW and BAW test structures for electrical and electroacoustic characterization of the films. A dielectric constant of 10 for AlN and 25 for Ti doped Ta2O5 have been measured. With respect to electroacoustic characterization, BAW measurements gave a longitudinal velocity of 11350 m/s and a TCD of -25ppm/K. AlN thin film test structures on SiO2/Si yielded a SAW velocity of around 5000 m/s, while those on polycrystalline diamond exhibited a SAW velocity of 11800 m/s. The latter results illustrate one of the biggest advantages of thin film SAW technology, namely one can exploit both the piezoelectric properties of the film and the acoustic properties of the substrate and hence devise components with superior performance. The explosive development of personal communications systems, navigation, satellite communications as well as personal computer and data processing systems together with the constant demand for higher speeds and larger bandwidths has driven the fabrication technology to its limits. This in turn necessitates the development of novel functional materials for the fabrication of devices with superior performance and higher capacity at reduced manufacturing costs. This thesis focuses on the synthesis and characterization of such materials for IC and electroacoustic applications. Specifically, AlN thin films as well as Ti doped Ta2O5 thin films have been grown using both RF and pulsed-DC reactive sputter deposition on a variety of substrate materials. AlN is a piezoelectric material and hence its crystallographic structure and film texture are of prime interest, while Ta2O5 is a material with a relatively high dielectric constant. A significant part of the work deals with the optimization of the deposition processes. The latter have been optimized both empirically and theoretically by modeling the reactive sputter process. Subsequently, highly textured AlN thin films have been synthesized and characterized. The films were fully c-axis oriented with a typical value for the FWHM of the (002) rocking curve of 1.6°. In addition, epitaxial AlN films have been grown on sapphire at 500oC with relatively low defect density.

The Cu(In,Ga)Se2-based thin film solar cell is a promising candidate for becoming one of the more important solar cell technologies in the near future. In order to realize such a development a significant reduced production cost of the Cu(In,Ga)Se2 (CIGS) layer is needed. This work shows a possible way towards such a reduction by increasing the deposition rate and decreasing the CIGS thickness with almost maintained device efficiency. Obtaining an improved device performance in CIGS-based solar cells by using an in-depth variation of the band gap has earlier been investigated without any clear conclusions. In this work an extensive experimental study of the beneficial effect of band gap profiling has been performed and firmly based conclusions have been made. For standard CIGS devices the band gap profiling can result in an improved efficiency of around 0.4 % units. This gain is related to improved field-assisted carrier collection. For reduced CIGS thicknesses the importance of a band gap profiling is enhanced, and at a CIGS thickness of 0.5 μm an efficiency gain of 2.5 % units is obtained, resulting in a 13.4 % efficient device. The main reason for the gain is passivation of the back contact, which becomes increasingly detrimental for the device performance as the CIGS thickness is reduced. With an optimized band gap profile the CIGS thickness can be reduced 3-4 times, with almost solely absorption related losses. The potential for increasing the deposition rate of co-evaporated CIGS layers is shown to be large. An increase of up to 10 times compared to commonly used deposition rates is possible with only minor losses in efficiency. By using band gap profiled thin CIGS layers deposited at high rates, the production from a single evaporation system can be increased up 30 times. Such an increase will lead to the needed reduction of the production cost of the complete solar cell module.

Electrically active point defects in semiconductor materials are important because they strongly affect material properties like effective doping concentration and charge carrier lifetimes. This thesis presents results on point defects introduced by ion implantation in silicon and silicon carbide. The defects have mainly been studied by deep level transient spectroscopy (DLTS) which is a quantitative, electrical characterization method highly suitable for point defect studies. The method is based on measurements of capacitance transients and both standard DLTS and new applications of the technique have been used. In silicon, a fundamental understanding of diffusion phenomena, like room-temperature migration of point defects and transient enhanced diffusion (TED), is still incomplete. This thesis presents new results which brings this understanding a step closer. In the implantation-based experimental method used to measure point defect migration at room temperature, it has been difficult to separate the effects of defect migration and ion channeling. For various reasons, the effect of channeling has so far been disregarded in this type of experiments. Here, a very simple method to assess the amount of channeling is presented, and it is shown that channeling dominates in our experiments. It is therefore recommended that this simple test for channeling is included in all such experiments. This thesis also contains a detailed experimental study on the defect distributions of vacancy and interstitial related damage in ion implanted silicon. Experiments show that interstitial related damage is positioned deeper (0.4 um or more) than vacancy related damage. A physical model to explain this is presented. This study is important to the future modeling of transient enhanced diffusion. Furthermore, the point defect evolution in low-fluence implanted 4H-SiC is investigated, and a large number of new defect levels has been observed. Many of these levels change or anneal out at temperatures below 300 C, which is not in accordance with the general belief that point defect diffusion in SiC requires high temperatures. This thesis also includes an extensive study on a metastable defect which we have observed for the first time and labeled the M-center. The defect is characterized with respect to DLTS signatures, reconfiguration barriers, kinetics and temperature interval for annealing, carrier capture cross sections, and charge state identification. A detailed configuration diagram for the M-center is presented. / QC 20101028

Thesis (M.S.)--Michigan State University. Dept. of Electrical and Computer Engineering, 2008. / "Thesis advisor, Dr. Edward J. Rothwell"--Acknowledgments. Title from PDF t.p. (viewed on July 29, 2009) Includes bibliographical references (p. 171-174). Also issued in print.

Thesis (M.S.)--University of Wisconsin--Madison, 1982. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaf 75).