TY - JOUR
T1 - Silicon Degradation in Monolithic II-VI/Si Tandem Solar Cells
AU - Tyler, Kevin D.
AU - Arulanandam, Madhan K.
AU - Pandey, Ramesh
AU - Kumar, Niranjana Mohan
AU - Drayton, Jennifer
AU - Sites, James R.
AU - King, Richard R.
N1 - Funding Information:
Manuscript received October 18, 2019; accepted December 2, 2019. Date of publication January 10, 2020; date of current version February 19, 2020. This work was supported by the National Science Foundation, Division of Electrical, Communications and Cyber Systems, EAGER Awards #1665299 and #1665508. (Corresponding author: Kevin D. Tyler.) K. D. Tyler, M. K. Arulanandam, N. M. Kumar, and R. R. King are with Arizona State University, Tempe, AZ 85281 USA (e-mail: kdtyler1@asu.edu; marulana@asu.edu; nmohanku@asu.edu; richard.r.king@asu.edu).
Publisher Copyright:
© 2011-2012 IEEE.
PY - 2020/3
Y1 - 2020/3
N2 - II-VI/Si tandem solar cells have strong potential for high efficiency at low cost by combining the two most widely used solar cell materials: silicon and cadmium telluride (CdTe). However, there are challenges with this merger, as loss of minority-carrier lifetime in the silicon bottom cell can be caused by growth of a II-VI cell on top. Silicon lifetime degradation in monolithic II-VI/Si structures is measured here on experimental samples for CdTe deposition temperatures between 400 and 500 °C, with variable In2O3:ZnO (IZO) thickness between the CdTe and silicon, and with and without CdCl2 postdeposition treatment. Results indicate that the CdCl2 treatment has the strongest effect on silicon lifetime reduction, followed by temperature and IZO thickness. Potential causes are discussed, and the effect on monolithic II-VI/Si two-junction solar cells is modeled. Remarkably, many silicon samples in the study were able to maintain >400 μs lifetimes, with some exceeding 1 ms, consistent with >30% projected efficiency in fully integrated II-VI/Si tandem solar cells.
AB - II-VI/Si tandem solar cells have strong potential for high efficiency at low cost by combining the two most widely used solar cell materials: silicon and cadmium telluride (CdTe). However, there are challenges with this merger, as loss of minority-carrier lifetime in the silicon bottom cell can be caused by growth of a II-VI cell on top. Silicon lifetime degradation in monolithic II-VI/Si structures is measured here on experimental samples for CdTe deposition temperatures between 400 and 500 °C, with variable In2O3:ZnO (IZO) thickness between the CdTe and silicon, and with and without CdCl2 postdeposition treatment. Results indicate that the CdCl2 treatment has the strongest effect on silicon lifetime reduction, followed by temperature and IZO thickness. Potential causes are discussed, and the effect on monolithic II-VI/Si two-junction solar cells is modeled. Remarkably, many silicon samples in the study were able to maintain >400 μs lifetimes, with some exceeding 1 ms, consistent with >30% projected efficiency in fully integrated II-VI/Si tandem solar cells.
KW - Cadmium telluride (CdTe)
KW - indium zinc oxide (IZO)
KW - lifetime degradation
KW - silicon
KW - tandem
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U2 - 10.1109/JPHOTOV.2019.2961607
DO - 10.1109/JPHOTOV.2019.2961607
M3 - Article
AN - SCOPUS:85080889836
SN - 2156-3381
VL - 10
SP - 690
EP - 695
JO - IEEE Journal of Photovoltaics
JF - IEEE Journal of Photovoltaics
IS - 2
M1 - 8956085
ER -