Defect Passivation for Perovskite Solar Cells: from Molecule Design to Device Performance

Abstract

Perovskite solar cells (PSCs) are a promising third‐generation photovoltaic (PV) technology developed rapidly in recent years. Further improvement of their power conversion efficiency is focusing on reducing the non‐radiative charge recombination induced by the defects in metal halide perovskites. So far, defect passivation by the organic small molecule has been considered as a promising approach for boosting the PSC performance owing to their large structure flexibility adapting to passivating variable kinds of defect states and perovskite compositions. Here, the recent progress of defect passivation toward efficient and stable PSCs was reviewed from the viewpoint of molecular structure design and device performance. To comprehensively reveal the structure‐performance correlation of passivation molecules, it was separately discussed how the functional groups, organic frameworks, and side chains affect the corresponding PV parameters of PSCs. Finally, a guideline was provided for researchers to select more suitable passivation agents, and a perspective was given on future trends in development of passivation strategies.

A self-arranged metal–organic polyhedron/fullerene asymmetric structure improves the performance of inverted perovskite solar cells

“…2f). 56 On the other hand, after replacing the PCBM ETL with the HRhMOP:PCBM ETL, t avg is reduced from 195.0 to 150.4 ns, implying a better electron extraction capability. We next fabricated the electron-only devices (ITO/PCBM/perovskite/ PCBM or HRhMOP:PCBM/Ag) and performed the space-chargelimited current (SCLC) analyses.…”

Heterogeneous FASnI3 Absorber with Enhanced Electric Field for High-Performance Lead-Free Perovskite Solar Cells

“…However, the surface highresolution C 1 s XPS spectra (Fig. S6) showed additional peaks at 287.1 eV (C-O-C group) and 288.0 eV (O=C-O group) in the FASnI 3 gradient sample [53], indicating the presence of PMMA on the surface after recrystallization, which could further induce surface passivation to reduce non-radiative recombination loss [54,55].…”

Effective Surface Passivation via Intermolecular Interactions for High‐Performance Perovskite Solar Cells

“…[18,19] Surface passivation atop perovskite films is a proven significant strategy to reduce non-radiation recombination and improve interface contact. [20][21][22][23][24][25] Snaith et al made pioneering work taking advantage of iodopenta-fluorobenzene (IPFB) to passivate excess iodide ions (I À ) on the surface of perovskite films through supramolecular halogen bonding interactions, thus reducing surface defects and improving device performance. [26] Subsequently, their group used pyridine/thiophene passivating uncoordinated lead ions (Pb 2þ ) on the perovskite surface to reduce the nonradiative recombination and improve the fluorescence lifetime of perovskite films.…”