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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Dielectric thin film applications for silicon solar cells

Song, Yang, Photovoltaics & Renewable Energy Engineering, Faculty of Engineering, UNSW January 2009 (has links)
Dielectric thin films have a long history in silicon photovoltaics. Due to the specific physical properties, they can function as passivation layer in solar cells. Also, they can be used as antireflection coating layers on top of the devices. They can improve the back surface reflectance if proper dielectric layers combination is used. What??s more, they can protect areas by masking during chemical etching, diffusion, metallization among the whole fabrication process. Crystalline silicon solar cell can be passivated by two ways: one is to deposit dielectric thin films to saturate the dangling bonds; the other is to introduce surface electrical field and repel back the minority carriers. This thesis explores thermally grown SiO2 and sputtered Si3N4(:H) to passivate n-type and thermal evaporation AlF3 to passivate p-type Float Zone silicon wafers, respectively. Sputtering is a cheap passivation method to replace PECVD in industry usage, but all sputtered samples are more likely to have encountered surface damage from neutral Ar and secondary electrons, both coming from the sputtered target. AlF3/SiO2 multi-layer stack is a negative charge combination; p inversion layer will form on the wafer surface. Light trapping is an important part in solar cell research work. In order to enhance the reflectance and improve the absorption possibility of near infrared photons, especially for high efficiency PERL cell application, the back surface structure is optimized in this work. Results show SiO2/Ag is a very good choice to replace SiO2/Al back reflectors. The maximum back surface reflectance is 97.82%. At the same time, SiO2/Ag has excellent internal angle dependence of reflectance, which is beneficial for surface textured cells. A ZnS/MgF2/SiO2/Al(Ag) superlattice can improve the back reflectance, but it is sensitive to incident angle inside the silicon wafer. If planar wafers are used to investigate all kinds of back reflectors, and an 8 degrees incident angle is fixed for typical spectrometry measurement, the results are easy to predict by Wvase software simulation. If a textured surface is considered, the light path inside the silicon wafer is very complicated and hard to calculate and simulate. The best way to evaluate the result is through experiment.
12

Hemoglobin oxygenation of a two-layer tissue-simulating phantom from time-resolved reflectance /

Hunter, Robert. January 2001 (has links)
Thesis ( Ph.D) -- McMaster University, 2001. / Includes bibliographical references. Also available via World Wide Web.
13

Detection of partial areas using remote sensing and hydrological analyses /

Kolawole, Michael O. January 1988 (has links) (PDF)
Thesis (M. Env. St.)--University of Adelaide, Centre for Environmental Studies, 1989. / Two coloured folded plates in pocket. Includes bibliographical references (leaves 97-107).
14

A CCD based bidirectional spectral reflectance field instrument /

Davis, Michael H. January 1990 (has links)
Thesis (M.S.)--Rochester Institute of Technology, 1990. / Spine title: Bidirectional spectral reflectance field instrument. Includes bibliographical references (leaves 68-69).
15

Reflectance sensors to predict mid-season nitrogen need of cotton

Oliveira, Luciane Farias de. Scharf, Peter C. January 2008 (has links)
The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file. Title from PDF of title page (University of Missouri--Columbia, viewed on October 2, 2009). Thesis advisor: Dr. Peter C. Scharf. Includes bibliographical references.
16

Local agency traffic sign retroreflectivity case study and model of observed traffic sign light intensity

Franz, Mark L., January 2009 (has links)
Thesis (M.S.)--West Virginia University, 2009. / Title from document title page. Document formatted into pages; contains viii, 85 p. : ill. (some col.), col. map. Includes abstract. Includes bibliographical references (p. 79-82).
17

Application of phenology to assist in hyperspectral species classification of a northern hardwood forest /

Sprehe, Gretchen M. January 2005 (has links)
Thesis (M.S.)--Rochester Institute of Technology, 2005. / Typescript. Includes bibliographical references (leaves 93-96).
18

Reflectometry with application to semiconductors

Veal, Boyd W. January 1969 (has links)
Thesis (Ph. D.)--University of Wisconsin--Madison, 1969. / Typescript. Vita. Description based on print version record. Includes bibliographical references.
19

Path-length determination of photons in mid-infrared diffuse reflection spectroscopy /

Averett, Lacey A. January 1900 (has links)
Thesis (Ph. D., Chemistry)--University of Idaho, December 2006. / Major professor: Peter R. Griffiths. Includes bibliographical references. Also available online (PDF file) by subscription or by purchasing the individual file.
20

Visible and near infrared reflectance spectroscopy of irregular solids /

Balkenhol, Michelle Rose, January 1992 (has links)
Thesis (Ph. D.)--University of Washington, 1992. / Vita. Includes bibliographical references (leaves [247]-251).

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