Research output: Contribution to journal › Article › peer-review
Optimization of Transparent Passivating Contact for Crystalline Silicon Solar Cells. / Kohler, Malte; Finger, Friedhelm; Rau, Uwe et al.
In: IEEE Journal of Photovoltaics, Vol. 10, No. 1, 8889659, 01.2020, p. 46-53.Research output: Contribution to journal › Article › peer-review
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TY - JOUR
T1 - Optimization of Transparent Passivating Contact for Crystalline Silicon Solar Cells
AU - Kohler, Malte
AU - Finger, Friedhelm
AU - Rau, Uwe
AU - Ding, Kaining
AU - Pomaska, Manuel
AU - Zamchiy, Alexandr
AU - Lambertz, Andreas
AU - Duan, Weiyuan
AU - Lentz, Florian
AU - Li, Shenghao
AU - Smirnov, Vladimir
AU - Kirchartz, Thomas
PY - 2020/1
Y1 - 2020/1
N2 - A highly transparent front contact layer system for crystalline silicon (c-Si) solar cells is investigated and optimized. This contact system consists of a wet-chemically grown silicon tunnel oxide, a hydrogenated microcrystalline silicon carbide [SiO2/μc-SiC:H(n)] prepared by hot-wire chemical vapor deposition (HWCVD), and a sputter-deposited indium doped tin oxide. Because of the exclusive use of very high bandgap materials, this system is more transparent for the solar light than state of the art amorphous (a-Si:H) or polycrystalline silicon contacts. By investigating the electrical conductivity of the μc-SiC:H(n) and the influence of the hot-wire filament temperature on the contact properties, we find that the electrical conductivity of μc-SiC:H(n) can be increased by 12 orders of magnitude to a maximum of 0.9 S/cm due to an increased doping density and crystallite size. This optimization of the electrical conductivity leads to a strong decrease in contact resistivity. Applying this SiO2/μc-SiC:H(n) transparent passivating front side contact to crystalline solar cells with an a-Si:H/c-Si heterojunction back contact we achieve a maximum power conversion efficiency of 21.6% and a short-circuit current density of 39.6 mA/cm2. All devices show superior quantum efficiency in the short wavelength region compared to the reference cells with a-Si:H/c-Si heterojunction front contacts. Furthermore, these transparent passivating contacts operate without any post processing treatments, e.g., forming gas annealing or high-temperature recrystallization.
AB - A highly transparent front contact layer system for crystalline silicon (c-Si) solar cells is investigated and optimized. This contact system consists of a wet-chemically grown silicon tunnel oxide, a hydrogenated microcrystalline silicon carbide [SiO2/μc-SiC:H(n)] prepared by hot-wire chemical vapor deposition (HWCVD), and a sputter-deposited indium doped tin oxide. Because of the exclusive use of very high bandgap materials, this system is more transparent for the solar light than state of the art amorphous (a-Si:H) or polycrystalline silicon contacts. By investigating the electrical conductivity of the μc-SiC:H(n) and the influence of the hot-wire filament temperature on the contact properties, we find that the electrical conductivity of μc-SiC:H(n) can be increased by 12 orders of magnitude to a maximum of 0.9 S/cm due to an increased doping density and crystallite size. This optimization of the electrical conductivity leads to a strong decrease in contact resistivity. Applying this SiO2/μc-SiC:H(n) transparent passivating front side contact to crystalline solar cells with an a-Si:H/c-Si heterojunction back contact we achieve a maximum power conversion efficiency of 21.6% and a short-circuit current density of 39.6 mA/cm2. All devices show superior quantum efficiency in the short wavelength region compared to the reference cells with a-Si:H/c-Si heterojunction front contacts. Furthermore, these transparent passivating contacts operate without any post processing treatments, e.g., forming gas annealing or high-temperature recrystallization.
KW - Passivating contact
KW - photovoltaic cells
KW - selective contact
KW - silicon
KW - silicon carbide
KW - solar cell
KW - transparent passivating contact (TPC)
KW - tunneling
KW - RECOMBINATION
KW - PERC
KW - CHEMICAL-VAPOR-DEPOSITION
KW - OPEN-CIRCUIT VOLTAGE
KW - TEMPERATURES
KW - SURFACE PASSIVATION
KW - JUNCTIONS
KW - FILAMENT
KW - HWCVD
KW - EFFICIENCY
UR - http://www.scopus.com/inward/record.url?scp=85077217714&partnerID=8YFLogxK
U2 - 10.1109/JPHOTOV.2019.2947131
DO - 10.1109/JPHOTOV.2019.2947131
M3 - Article
AN - SCOPUS:85077217714
VL - 10
SP - 46
EP - 53
JO - IEEE Journal of Photovoltaics
JF - IEEE Journal of Photovoltaics
SN - 2156-3381
IS - 1
M1 - 8889659
ER -
ID: 22850106