Full metadata
Title
High efficiency GaAs-based solar cells simulation and fabrication
Description
GaAs-based solar cells have attracted much interest because of their high conversion efficiencies of ~28% under one sun illumination. The main carrier recombination mechanisms in the GaAs-based solar cells are surface recombination, radiative recombination and non-radiative recombination. Photon recycling reduces the effect of radiative recombination and is an approach to obtain the device performance described by detailed balance theory. The photon recycling model has been developed and was applied to investigate the loss mechanisms in the state-of-the-art GaAs-based solar cell structures using PC1D software. A standard fabrication process of the GaAs-based solar cells is as follows: wafer preparation, individual cell isolation by mesa, n- and p-type metallization, rapid thermal annealing (RTA), cap layer etching, and anti-reflection coating (ARC). The growth rate for GaAs-based materials is one of critical factors to determine the cost for the growth of GaAs-based solar cells. The cost for fabricating GaAs-based solar cells can be reduced if the growth rate is increased without degrading the crystalline quality. The solar cell wafers grown at different growth rates of 14 μm/hour and 55 μm/hour were discussed in this work. The structural properties of the wafers were characterized by X-ray diffraction (XRD) to identify the crystalline quality, and then the as-grown wafers were fabricated into solar cell devices under the same process conditions. The optical and electrical properties such as surface reflection, external quantum efficiency (EQE), dark I-V, Suns-Voc, and illuminated I-V under one sun using a solar simulator were measured to compare the performances of the solar cells with different growth rates. Some simulations in PC1D have been demonstrated to investigate the reasons of the different device performances between fast growth and slow growth structures. A further analysis of the minority carrier lifetime is needed to investigate into the difference in device performances.
Date Created
2014
Contributors
- Zhang, Chaomin (Author)
- Honsberg, Christiana (Thesis advisor)
- Goodnick, Stephen (Committee member)
- Faleev, Nikolai (Committee member)
- Arizona State University (Publisher)
Topical Subject
Resource Type
Extent
xi, 78 p. : ill. (chiefly col.), col. map
Language
Copyright Statement
In Copyright
Primary Member of
Peer-reviewed
No
Open Access
No
Handle
https://hdl.handle.net/2286/R.I.24949
Statement of Responsibility
by Chaomin Zhang
Description Source
Viewed on Aug. 4, 2014
Level of coding
full
Note
Partial requirement for: M.S., Arizona State University, 2014
Note type
thesis
Includes bibliographical references (p. 73-78)
Note type
bibliography
Field of study: Electrical engineering
System Created
- 2014-06-09 02:10:41
System Modified
- 2021-08-30 01:35:08
- 2 years 8 months ago
Additional Formats