TY - GEN
T1 - First principles modeling of grain boundaries in CdTe
AU - Sen, Fatih G.
AU - Buurma, Christopher
AU - Paulauskas, Tadas
AU - Sun, Ce
AU - Kim, Moon
AU - Sivananthan, Sivalingam
AU - Klie, Robert F.
AU - Chan, Maria K.Y.
N1 - Funding Information:
National Science Foundation grant
Funding Information:
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],
Publisher Copyright:
© 2017 IEEE.
PY - 2017
Y1 - 2017
N2 - 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.
AB - 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.
KW - CdTe
KW - Density functional theory
KW - Grain boundaries
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U2 - 10.1109/PVSC.2017.8366792
DO - 10.1109/PVSC.2017.8366792
M3 - Conference contribution
AN - SCOPUS:85048460541
T3 - 2017 IEEE 44th Photovoltaic Specialist Conference, PVSC 2017
SP - 1610
EP - 1613
BT - 2017 IEEE 44th Photovoltaic Specialist Conference, PVSC 2017
PB - Institute of Electrical and Electronics Engineers Inc.
T2 - 44th IEEE Photovoltaic Specialist Conference, PVSC 2017
Y2 - 25 June 2017 through 30 June 2017
ER -
