Laser‐Generated Nanocrystals in Perovskite: Universal Embedding of Ligand‐Free and Sub‐10 nm Nanocrystals in Solution‐Processed Metal Halide Perovskite Films for Effectively Modulated Optoelectronic Performance

Abstract

Regulating the chemical/physical features of solution processed metal halide perovskite films by integrating sub‐10 nm nanocrystals is a highly promising strategy to advance their outstanding optoelectronic performance. However, significant challenges remain for the universal embedding of the well‐defined nanocrystals in the film matrix. By generating nanocrystals in desired solvents via pulsed laser irradiation in liquid, the authors demonstrate the effective decoration of sub‐10 nm nanocrystals in perovskite films for enhanced optoelectronic performance. It is believed that this improved performance is due to the modification of the widely adopted “antisolvent” to a novel “anti‐colloidal‐solution” (ACS). Exemplified by a typical ACS; carbon dots in chlorobenzene, its encouraging superiority in regulating, not only the films morphology, but also the electronic structure, is demonstrated. This results in perovskite solar cells with a champion efficiency of 21.41% as well as a pronounced stability over 5000 h in relative humidity of 40%. The capability of nanocrystal embedding for boosted photovoltaic performance is further exploited by employing other laser generated ACSs. Such a strategy may open up a route to regulating hybrid perovskite film performance via nanocrystal embedding for photovoltaics or even beyond optoelectronic applications.

Double Barriers for Moisture Degradation: Assembly of Hydrolysable Hydrophobic Molecules for Stable Perovskite Solar Cells with High Open‐Circuit Voltage

“…The distribution of the oligomer can be observed through the cross-sectional backscattered scanning electron (BSE) imaging due to the atomic number difference reflected by strength of backscattered electron signals. [33] It can be depicted from Figure 1b that distinct black regions are separately dispersed throughout the entire layer if comparing to that of control layer (Figure S2, Supporting Information). Energy dispersive X-ray spectroscopy in the cross-sectional SEM (SEM-EDS) observations (Figure 1c) reveals distribution of F and Si elements (characteristic elements in PFTS) in the entire perovskite layer (according to the Pb element distribution).…”

Recent advances on interfacial engineering of hematite photoanodes for viable photo‐electrochemical water splitting

“…Surface modification with various catalytic and non‐catalytic materials was shown to be an effective strategy to improve the performance of hematite 13,65 . In addition, lattice mismatch or Schottky contact at hematite/substrate interface may result in the formation of Fermi level pinning 66 and energy barrier, 60,67 which are infavorable for the carriers separation and transport.…”

Observing Defect Passivation of the Grain Boundary with 2‐Aminoterephthalic Acid for Efficient and Stable Perovskite Solar Cells

“…Fortunately, several recent studies have reported that additive engineering is an effective alternative strategy. Various additives, such as polymers, small molecules, and semiconductor molecules, have been incorporated into perovskite precursor solutions . Although additives containing N, O, and S atoms with lone pairs of electrons were found to be efficient in passivating defects in perovskite films and further enhanced charge transfer and collection, they lacked sufficient evidence to demonstrate that the defect passivation undoubtedly occurred at GBs .…”