Asymmetrical A-DA′D-A–type electron transport materials with enhanced electron mobility and water-resistant interface for perovskite solar cells

TY - JOUR

T1 - Asymmetrical A-DA′D-A–type electron transport materials with enhanced electron mobility and water-resistant interface for perovskite solar cells

AU - Guo, Qian

AU - Li, Quan Song

N1 - Publisher Copyright: © 2025

PY - 2025/5/1

Y1 - 2025/5/1

N2 - Organic small-molecule electron transport materials (ETMs) exhibit fantastic potential in achieving high power conversion efficiency (PCE) of perovskite solar cells (PSCs). In this work, the novel asymmetric naphthalene diimide (NDI) derivatives were designed by fused-ring engineering and end-group engineering based on the symmetric NDI-based E molecule. These asymmetric NDI derivatives are designed by tuning thiophene units (A1, A2, and A3), introducing heteroatoms into the donor (B1, B2), and introducing asymmetric end groups (C1, C2, and C3). Quantum chemical calculations show that the energy levels of ETMs match well with MAPbI3. In addition, a strong linear correlation (R2 > 0.96) is observed between the LUMO energies, adiabatic electron affinities, and reorganization energies. Notably, the electron mobility of the asymmetric molecule B1 is enhanced by 16 times (0.851 cm2V−1s−1) compared to the symmetric E molecule (0.053 cm2V−1s−1). The calculation shows that the designed asymmetric molecules exhibit robust interaction with perovskite, and the Bader charge indicates enhanced electron injection from the perovskite to the ETM. Furthermore, molecular dynamics simulations verified that the asymmetric structure (A2 and C3) can effectively prevent water from invading the perovskite surface. This asymmetric molecular design strategy provides insights for designing novel ETM for high performance PSCs.

AB - Organic small-molecule electron transport materials (ETMs) exhibit fantastic potential in achieving high power conversion efficiency (PCE) of perovskite solar cells (PSCs). In this work, the novel asymmetric naphthalene diimide (NDI) derivatives were designed by fused-ring engineering and end-group engineering based on the symmetric NDI-based E molecule. These asymmetric NDI derivatives are designed by tuning thiophene units (A1, A2, and A3), introducing heteroatoms into the donor (B1, B2), and introducing asymmetric end groups (C1, C2, and C3). Quantum chemical calculations show that the energy levels of ETMs match well with MAPbI3. In addition, a strong linear correlation (R2 > 0.96) is observed between the LUMO energies, adiabatic electron affinities, and reorganization energies. Notably, the electron mobility of the asymmetric molecule B1 is enhanced by 16 times (0.851 cm2V−1s−1) compared to the symmetric E molecule (0.053 cm2V−1s−1). The calculation shows that the designed asymmetric molecules exhibit robust interaction with perovskite, and the Bader charge indicates enhanced electron injection from the perovskite to the ETM. Furthermore, molecular dynamics simulations verified that the asymmetric structure (A2 and C3) can effectively prevent water from invading the perovskite surface. This asymmetric molecular design strategy provides insights for designing novel ETM for high performance PSCs.

KW - Asymmetric organic molecules

KW - Density functional theory

KW - Descriptor

KW - Interfacial properties

KW - Perovskite solar cells

KW - Water-resistant interface

UR - https://www.scopus.com/pages/publications/86000295305

U2 - 10.1016/j.solener.2025.113409

DO - 10.1016/j.solener.2025.113409

M3 - Article

AN - SCOPUS:86000295305

SN - 0038-092X

VL - 291

JO - Solar Energy

JF - Solar Energy

M1 - 113409

ER -