Stress Relaxation for Lead Iodide Nucleation in Efficient Perovskite Solar Cells.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 39840590.
- Also identified by DOI 10.1002/adma.202412304.
- No licence information is recorded for this record.
- Because redistribution is not established, this page shows the abstract only. Follow the links below for the full text.
Abstract
Porous lead iodide (PbI<sub>2</sub>) film is crucial for the complete reaction between PbI<sub>2</sub> and ammonium salts in sequential-deposition technology so as to achieve high crystallinity perovskite film. Herein, it is found that the tensile stress in tin (IV) oxide (SnO<sub>2</sub>) electron transport layer (ETL) is a key factor influencing the morphology and crystallization of PbI<sub>2</sub> films. Focusing on this, lithium trifluoromethanesulfonate (LiOTf) is used as an interfacial modifier in the SnO<sub>2</sub>/PbI<sub>2</sub> interface to decrease the tensile stress to reduce the necessary critical Gibbs free energy for PbI<sub>2</sub> nuclei formation. The relaxed tensile stress facilitates the more porous PbI<sub>2</sub> generation with larger particles and higher roughness, resulting in superior-quality perovskite films. Besides, this strategy effectively passivates the inherent electron traps of SnO<sub>2</sub> and smooths the interfacial energy levels, boosting the charge extraction and transfer. As a result, a champion power conversion efficiency (PCE) of 25.33% (25.10% stabilized for 600 s) is achieved. Furthermore, the device demonstrates exceptional stability, retaining 90% of its initial PCE at its maximum power point tracking measurement (under 100 mW cm<sup>-2</sup> white light illumination at ≈55 °C temperature, in N<sub>2</sub> atmosphere) after 600 h.