Meniscus-assisted solution printing of large-grained perovskite films for high-efficiency solar cells

Abstract

Control over morphology and crystallinity of metal halide perovskite films is of key importance to enable high-performance optoelectronics. However, this remains particularly challenging for solution-printed devices due to the complex crystallization kinetics of semiconductor materials within dynamic flow of inks. Here we report a simple yet effective meniscus-assisted solution printing (MASP) strategy to yield large-grained dense perovskite film with good crystallization and preferred orientation. Intriguingly, the outward convective flow triggered by fast solvent evaporation at the edge of the meniscus ink imparts the transport of perovskite solutes, thus facilitating the growth of micrometre-scale perovskite grains. The growth kinetics of perovskite crystals is scrutinized by in situ optical microscopy tracking to understand the crystallization mechanism. The perovskite films produced by MASP exhibit excellent optoelectronic properties with efficiencies approaching 20% in planar perovskite solar cells. This robust MASP strategy may in principle be easily extended to craft other solution-printed perovskite-based optoelectronics.

Hybrid PbS Quantum‐Dot‐in‐Perovskite for High‐Efficiency Perovskite Solar Cell

“…Elemental analysis demonstrates the anticipated stoichiometric ratio of 1:1 for Pb:S. The microstructure details of MAPbI 3 was achieved by TEM analysis accompanied with the FFT‐SAD. Figure S4 (Supporting Information) shows a typical HRTEM image of pure MAPbI 3 materials, the lattice spacing of 3.0 Å matches well with the crystalline planar (220) of MAPbI 3 . The lattice orientation of MAPbI 3 in TEM image keeps at almost the same direction, suggesting that the MAPbI 3 has an ideal crystalline structure.…”

Engineering Halide Perovskite Crystals through Precursor Chemistry

“…Figure d schematically depicts the blade coating process based on heat‐assisted method. The meniscus precursor solution edge appears between the hot substrate (typically 70–145 °C) and an upper plate, which constrains the diffusion of perovskite precursor solution due to capillary action . As solvent evaporates, the meniscus at the edge drives an outward convective flow and the perovskite solute moves toward the solid/liquid boundary.…”

Understanding the Effect of Different Synthesis Conditions on the Physicochemical Properties of Mixed‐Ion Perovskite Solar Cells

“…Rate constants around four times lower were observed for the nonradiative luminescence decay processes for perovskite material made in vacuum flash‐assisted solution processing compared with that produced from conventional one‐step solution deposition . Similarly, longer emission decays were observed upon applying meniscus‐assisted solution printing instead of the spin‐coating method to form the perovskite layer . Perovskites in PbI 2 ‐rich grains exhibited a longer lifetime owing to the suppression of defect trapping .…”