TY - JOUR
T1 - Enhanced charge extraction in textured perovskite-silicon tandem solar cells via molecular contact functionalization
AU - Huang, Jian
AU - Zhang, Letian
AU - Yilmaz, Cem
AU - Qu, Geping
AU - Zemer, Ido
AU - Hooijer, Rik
AU - Cai, Siyuan
AU - Buyruk, Ali
AU - Zhu, Hao
AU - Bouraoui, Meriem
AU - Hartschuh, Achim
AU - Mishima, Ryota
AU - Yamamoto, Kenji
AU - Deger, Caner
AU - Yavuz, Ilhan
AU - Jen, Alex K.Y.
AU - Ugur, Esma
AU - De Wolf, Stefaan
AU - Levine, Igal
AU - Xu, Zong Xiang
AU - Aydin, Erkan
N1 - Publisher Copyright:
© 2025 The Author(s).
PY - 2026/1/21
Y1 - 2026/1/21
N2 - High-efficiency perovskite-silicon tandem solar cells require effective charge recombination at the interconnecting junction. On textured silicon bottom cells, conventional alkyl-chain-based self-assembled molecules (SAMs) tend to aggregate, limiting device performance. To overcome this, we synthesized a conjugated linker SAM, (4-(7 H -dibenzo[ c , g ]carbazol-7-yl)phenyl)phosphonic acid (Bz-Ph p PACz), enabling efficient charge transport. Our molecular design included controlling bromine (Br) impurities in the SAM precursors, as chemical analysis revealed that commercial 4PADCB contains trace bromine species that passivate interface defects. We optimized the molecular mixture by precisely blending brominated and non-brominated counterparts. The conjugated framework promotes charge transport on rough surfaces, while bromine improves energy alignment, passivates defects, and relieves lattice strain in the perovskite layer. This approach yielded perovskite-silicon tandem cells on Czochralski (CZ) silicon with 31.4% efficiency, highlighting the critical role of molecular design and impurity control in achieving high-performance tandem devices.
AB - High-efficiency perovskite-silicon tandem solar cells require effective charge recombination at the interconnecting junction. On textured silicon bottom cells, conventional alkyl-chain-based self-assembled molecules (SAMs) tend to aggregate, limiting device performance. To overcome this, we synthesized a conjugated linker SAM, (4-(7 H -dibenzo[ c , g ]carbazol-7-yl)phenyl)phosphonic acid (Bz-Ph p PACz), enabling efficient charge transport. Our molecular design included controlling bromine (Br) impurities in the SAM precursors, as chemical analysis revealed that commercial 4PADCB contains trace bromine species that passivate interface defects. We optimized the molecular mixture by precisely blending brominated and non-brominated counterparts. The conjugated framework promotes charge transport on rough surfaces, while bromine improves energy alignment, passivates defects, and relieves lattice strain in the perovskite layer. This approach yielded perovskite-silicon tandem cells on Czochralski (CZ) silicon with 31.4% efficiency, highlighting the critical role of molecular design and impurity control in achieving high-performance tandem devices.
KW - bromine substitution
KW - conjugated linker
KW - perovskite-silicon tandem solar cells
KW - self-assembled molecules
UR - https://www.scopus.com/pages/publications/105025170240
U2 - 10.1016/j.joule.2025.102227
DO - 10.1016/j.joule.2025.102227
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AN - SCOPUS:105025170240
SN - 2542-4351
VL - 10
JO - Joule
JF - Joule
IS - 1
M1 - 102227
ER -