Description
This dissertation details a study of wide-bandgap molecular beam epitaxy (MBE)-grown single-crystal MgxCd1-xTe. The motivation for this study is to open a pathway to reduced $/W solar power generation through the development of a high-efficiency 1.7-eV II-VI top cell current-matched to low-cost 1.1-eV silicon. This paper reports the demonstration of monocrystalline 1.7-eV MgxCd1-xTe/MgyCd1-yTe (y>x) double heterostructures (DHs) with a record carrier lifetime of 560 nanoseconds, along with a 1.7-eV MgxCd1-xTe/MgyCd1-yTe (y>x) single-junction solar cell with a record active-area efficiency of 15.2% and a record open-circuit voltage (VOC) of 1.176 V. A study of indium-doped n-type 1.7-eV MgxCd1-xTe with a carrier activation of up to 5 × 1017 cm-3 is presented with promise to increase device VOC. Finally, this paper reports an epitaxial lift-off (ELO) technology using water-soluble MgTe for the creation of free-standing MBE-grown II-VI single-crystal CdTe and 1.7-eV MgxCd1-xTe solar cells freed from lattice-matched InSb(001) substrates. Photoluminescence (PL) spectroscopy measurements comparing intact and free-standing films reveal the survival of optical quality in CdTe DHs after ELO. This technology opens up several possibilities to drastically increase cell conversion efficiency through improved light management and transferability into monolithic multijunction devices. Lastly, this report will present considerations for future work in each of the study areas mentioned above.
Details
Title
- Molecular beam epitaxial growth of monocrystalline MgxCd1-xTe/MgyCd1-yTe (x<y) double heterostructures and solar cells
Contributors
- Campbell, Calli Michele (Author)
- Zhang, Yong-Hang (Thesis advisor)
- Chan, Candance K (Committee member)
- King, Richard R (Committee member)
- Arizona State University (Publisher)
Date Created
The date the item was original created (prior to any relationship with the ASU Digital Repositories.)
2019
Subjects
Resource Type
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Note
- thesisPartial requirement for: Ph.D., Arizona State University, 2019
- bibliographyIncludes bibliographical references (pages 111-117)
- Field of study: Materials science and engineering
Citation and reuse
Statement of Responsibility
by Calli Michele Campbell