Anchoring Vertical Dipole to Enable Efficient Charge Extraction for High‐Performance Perovskite Solar Cells

Abstract

Perovskite solar cells (PSCs) via two-step sequential method have received great attention in recent years due to their high reproducibility and low processing costs. However, the relatively high trap-state density and poor charge carrier extraction efficiency pose challenges. Herein, highly efficient and stable PSCs via a two-step sequential method are fabricated using organic-inorganic (OI) complexes as multifunctional interlayers. In addition to reduce the under-coordinated Pb 2+ ions related trap states by forming interactions with the functional groups, the complexes interlayer tends to form dipole moment which can enhance the built-in electric field, thus facilitating charge carrier extraction. Consequently, with rational molecular design, the resulting devices with a vertical dipole moment that parallels with the built-in electric field yield a champion efficiency of 23.55% with negligible hysteresis. More importantly, the hydrophobicity of the (OI) complexes contributes to an excellent ambient stability of the resulting device with 91% of initial efficiency maintained after 3000 h storage.

Targeting the imperfections at the ZnO/CsPbI2Br interface for low-temperature carbon-based perovskite solar cells

“…3e-h, the doped ZnO ETLs exhibited a higher contact potential difference than the pristine ZnO ETL, indicating that the cesium modulators could decrease the W F of ZnO owing to the formation of a Zn-O-Cs interfacial dipole. 12,14,37,[42][43][44][45] Ultraviolet photoelectron spectroscopy (UPS) was further performed to quantitatively illustrate the interfacial energy level alignment. As exhibited in Fig.…”

Small Molecules Functionalized Zinc Oxide Interlayers for High Performance Low‐Temperature Carbon‐Based CsPbI2Br Perovskite Solar Cells

“…As shown in Figure S14, Supporting Information, the doped ZnO films presented larger contact potential difference (CPD) than that of reference one, which means decreased W F values. [11,54,55] The reduced W F values would enhance the energy level alignment and electronic coupling between ZnO and perovskite films, thereby reducing charge accumulation/recombination and enhancing the open-circuit voltage (V oc ) of PSCs. [40,51,52,56,57] Hence, the above results indicate that the doped ZnO films are effective interfacial energy level adjustment layers.…”

Fine-tuning chemical passivation over photovoltaic perovskites by varying the symmetry of bidentate acceptor in D–A molecules

“…2b and c), conrming that the terminal groups of bidentate molecules could interact with under-coordinated Pb 2+ defects. Strangely, the larger shis of binding energy for Pb 4f and N 1s occur in perovskite lm passivated by TA-MN and indicate a better passivation capacity of TA-MN than that of TA-CA, 32,35 which is worth a profound investigation. In addition, the Fourier transform infrared spectra (FTIR) of D-A molecules with and without PbI 2 were performed (Fig.…”