Post on 08-Jul-2020
Ge/GaAs/InGaP Triple-Junction Solar Cells for
Space ExplorationSANAT PANDEY
ECE 443 TCAD Project
Outline
▪ Motivation
▪ Technical Background
▪ Design and Related Physics
▪ Simulation Results
▪ Conclusion
Outline
▪ Motivation
▪ Technical Background
▪ Design and Related Physics
▪ Simulation Results
▪ Conclusion
▪ Spacecrafts such as Europa Clipper rely on Solar Cells for
functionality
▪ Have strict weight limit to be met
▪ Reduce the number of Cells
▪ Generate same power
▪ Higher maneuverability
▪ Reduce cost of lifting a payload into space, manufacturing,
and assembly
Motivation
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Outline
▪ Motivation
▪ Technical Background
▪ Design and Related Physics
▪ Simulation Results
▪ Conclusion
▪ 𝐼 𝑉 = 𝐼𝑜𝑝 − 𝐼0 𝑒𝑞 𝑉+𝐼𝑅𝑆
𝑘𝑇 − 1 −𝑉+𝐼𝑅𝑆
𝑅𝑠ℎ
▪ 𝐹𝑖𝑙𝑙 𝐹𝑎𝑐𝑡𝑜𝑟 𝐹𝐹 =𝑉𝑚𝑝𝐼𝑚𝑝
𝑉𝑜𝑐𝐼𝑠𝑐
▪ 𝐸𝑓𝑓𝑖𝑐𝑖𝑒𝑛𝑐𝑦 𝜂 =𝑉𝑜𝑐𝐼𝑠𝑐𝐹𝐹
𝑃𝑖𝑛, where Pin is
the input power
Technical Background
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Equivalent Circuit [1]IV Curve and Output Power [1]
Photon Absorption Mechanism [1]
[1] Tao, Yuguo & Rohatgi, Ashish. “High‐Efficiency Front
Junction n‐Type Crystalline Silicon Solar Cells”, Intech
Open, http://dx.doi.org/10.5772/65023 (2017)
Triple Junction over single or
double junction Solar Cell to
reduce Thermalization
Design and Related Physics
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Thermalization [2]
[2] K. E. Jasim, “Quantum Dot Solar Cells”,
Intech Open, http://dx.doi.org/10.5772/59159
(2018)
Wavelength Spectrum Covered [3]
[3] P. Michalopoulos, “A novel approach for the development and optimization of
state-of-the-art photovoltaic devices using Silvaco,” M.S. thesis, Dept. of Elec.
and Comp. Engr., Naval Postgraduate School, Monterey, CA, 2002.
Design and Related Physics Continued
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0
500
1000
1500
2000
2500
0 500 1000 1500 2000 2500
Inte
nsi
ty (
W/m
2)
Wavelength (nm)
Solar Irradiance Comparison of Earth and
Jupiter
Jupiter
Earth 𝐻 = 𝐻𝑠𝑢𝑛𝑅𝑠𝑢𝑛2
𝐷2
Solar Constant: Earth = 1353 W/m2
Jupiter = 50 W/m2
Intensity reduces by a factor of 27.06!!!
Solar Radiation In Space, https://pvcdrom.pveducation.org/SUNLIGHT/SPACE.HTM, Accessed on 2019-04-21
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Simulation Results
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0.00
0.10
0.20
0.30
0.40
0.50
0.60
0.70
0.00 0.50 1.00 1.50 2.00 2.50
Curr
ent
Den
sity
(m
A/c
m2)
Voltage (V)
JV Chracteristic for Model 1
Jsc= 0.613 mA/cm2
Voc ~ 2.3 V
FF= 89.24%
Efficiency= 25.394%
Simulation Results
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Energy Band Diagram
Current Density Distribution
Cross-sectional Current
Relative energy density
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Ge (m) GaAs (m)
InGaP (m)
Width (m)
TJ Doping Compared to model 1
Eff (%)
11 3.5 0.45 5 Model 1 25.39420 3.5 0.45 5 Same 25.62820 6.4 0.45 5 Same 25.63220 6.4 0.82 5 Same 24.16420 6.4 0.82 10 Same 23.98320 6.4 0.82 15 Same 24.03511 3.5 0.45 10 Same 25.22011 3.5 0.45 8 Same 22.95111 3.5 0.45 5 Double 25.46115 4.8 0.62 10 Double 24.95215 5 0.8 10 Double 25.23915 5 0.8 15 Double 25.29820 5 0.8 15 Double 25.40520 6.4 0.82 10 Double 23.985
▪ Drop in Intensity affects the efficiency more than predicted
▪ Modifying parameters to find an optimal point of high
efficiency for Ge/GaAs/InGaP triple junction cells
▪ Research in InGaN/GaN solar cells: vary the In and Ga
content in InGaN, we can get cover the whole solar
irradiance.
Conclusion
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THANK YOU!
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