The passivation of defects at perovskite grain boundaries (GB) is crucial in achieving highly efficient and stable perovskite solar cells. Unlike the widely used additive passivation method where a mixture of additives and perovskite precursor is used for preparing perovskite films, we herein developed a new defect post-healing method via dip-coating trioctylphosphine oxide (TOPO) ligands on pre-fabricated carbon-based mesoscopic perovskite solar cells (MPSCs). Since perovskites have formed before post-healing, TOPO ligands are selectively adsorbed onto the exposed perovskite surface and hence have little influence on charge extraction of interfaces. The defects are post-healed via O atoms in PO bonds coordinated to halide-deficient sites, leading to an enhancement of the power conversion efficiency (PCE) from 11.0% to 12.8%. Moreover, due to the three hydrophobic long chain alkyls in TOPO, the humidity stability of the device has also been improved simultaneously.

Rhenium disulfide (ReS ₂ ) is an interesting kind of transition metal dichalcogenide (TMD) because of its thickness-independent and suitable direct-bandgap structure, which could enable highly efficient solar-energy conversion efficiency. Here, we demonstrate an ultrasonic liquid exfoliation technique in combination with grinding to produce high quality ReS ₂ nanosheets (NSs) on a large scale. After combination with TiO ₂ nanoparticles, the co-catalytic performance of TiO ₂ @ReS ₂ nanocomposites is investigated, which presents dramatically enhanced degradation activity of organic pigments under sunlight illumination in comparison with pure TiO ₂ nanoparticles. The underlying mechanism of enhanced photocatalytic activity can be attributed to improved separation efficiency of photogenerated electron–hole pairs in TiO ₂ @ReS ₂ nanocomposites, which is confirmed by photoluminescence analysis and photoelectrochemical measurements. Our results demonstrate that the layered ReS ₂ NS is a promising two-dimensional supporting platform for photocatalysis and moreover it could also provide a new perspective on TMDs co-catalyst.

Pulsed laser deposition (PLD) is a simple and extremely versatile technique to grow thin films and nanomaterials from a wide variety of materials. Compared to traditional fabrication methods, PLD is a clean physical vapour deposition approach that avoids complicated chemical reactions and by-products, achieving a precise stochiometric transfer of the target material onto the substrate and providing control over the film thickness. Halide perovskite materials have attracted extensive attention due to their excellent photoelectric and photovoltaic properties. In this paper, we present an overview of the fundamental and practical aspects of PLD. The properties and preparation methods of the halide perovskite materials are briefly discussed. Finally, we will elaborate on recent research on the preparation of perovskite solar cells by PLD, summarize the advantages and disadvantages of the PLD preparation, and prospect the all-vacuum PLD-grown solar cells in a full solar cell structure.