Abstract
A fundamental understanding of the role of vacancies, interstitials, dislocations and grain boundaries on the electronic structure of CdTe may lead to efficiency improvements. Atomistic-level characterization, including microscopy and first principles modeling, is crucial in developing such a fundamental understanding. In the present work, we built atomistic grain boundary and dislocation core models directly from the STEM images using image analysis methods and crystallographic information at the interface. Grain boundaries are modeled using first principles density functional theory (DFT) calculations. Electronic structures of large-scale grain models are also computed with an accurate hybrid functional (HSE06). We report the electronic density of states (DOS) and electrostatic potential profiles of different CdTe grain boundaries to understand charge carrier interactions. Thermodynamics of point defects and pairs of point defects that can exist on or near grain boundaries are studied and pertaining changes in electronic structure are reported. The implications of these electronic structure changes at grain boundaries on photovoltaic performance, and corresponding strategies to improve performance, are discussed.
Original language | English (US) |
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Title of host publication | 2017 IEEE 44th Photovoltaic Specialist Conference, PVSC 2017 |
Publisher | Institute of Electrical and Electronics Engineers Inc. |
Pages | 1610-1613 |
Number of pages | 4 |
ISBN (Electronic) | 9781509056057 |
DOIs | |
State | Published - 2017 |
Event | 44th IEEE Photovoltaic Specialist Conference, PVSC 2017 - Washington, United States Duration: Jun 25 2017 → Jun 30 2017 |
Publication series
Name | 2017 IEEE 44th Photovoltaic Specialist Conference, PVSC 2017 |
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Other
Other | 44th IEEE Photovoltaic Specialist Conference, PVSC 2017 |
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Country/Territory | United States |
City | Washington |
Period | 6/25/17 → 6/30/17 |
Funding
National Science Foundation grant We acknowledge funding from the DoE Sunshot program under contract # DOE DEEE005956. Use of the Center for Nanoscale Materials, an Office of Science user facility, was supported by the U. S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357. This work used the Extreme Science and Engineering Discovery Environment (XSEDE) [16],
Keywords
- CdTe
- Density functional theory
- Grain boundaries
ASJC Scopus subject areas
- Renewable Energy, Sustainability and the Environment
- Electrical and Electronic Engineering
- Electronic, Optical and Magnetic Materials