Investigation of sub-bandgap absorption in iron pyrite : optical and electrical measurements
Name
880676056-MIT.pdf
Description
Full printable version
Size
4.72 MB
Format
Adobe PDF
Checksum (MD5)
97b823edfb9b2dc465760d38557695a2
Author(s)
Chakraborty, Rupak
Advisor(s)
Tonio Buonassisi.
Date Issued
2014
Publisher
Massachusetts Institute of Technology
Abstract
We investigate sub-bandgap absorption in pyrite FeS₂ single-crystals, using both natural and synthetic crystals. Both types of crystals show non-negligible magnitudes of sub-bandgap absorption. To test whether the origin of the residual sub-bandgap absorption is partially due to a lower bulk bandgap than previously thought, we conduct temperature-dependent electrical measurements on natural and synthetic crystals. Unlike previous measurements on pyrite, our electrical measurements are done in a sulfur atmosphere to avoid FeS formation. Using conductivity data in the intrinsic regime along with extrapolated Hall mobility data, the extracted bandgap is more than 0.1 eV lower than the literature value of 0.95 eV. However, higher-temperature Hall data are needed to gain a more reliable bandgap estimate.
Description
Thesis: S.M., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2014.
Cataloged from PDF version of thesis.
Includes bibliographical references (pages 67-70).
Subjects
Mechanical Engineering.
MIT Department
Massachusetts Institute of Technology. Department of Mechanical Engineering
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