van der Waals Lamination for Integrating Metal Halide in Perovskite Optoelectronic Devices.

Metal halide perovskites (MHPs) have emerged as promising materials for optoelectronic applications owing to their exceptional optoelectronic properties such as high absorption coefficients, tunable bandgaps, and low-cost solution processability. However, integrating MHPs with other functional components for optoelectronic device fabrication remains challenging because of limited thermal stability and solvent sensitivity, resulting in their incompatibility with conventional processing techniques. To address these challenges, van der Waals (vdW) lamination has emerged as an alternative "damage-free" integration approach. This review compares vdW lamination with conventional integration methods, highlighting the fundamental principles and distinct advantages of the vdW lamination approach. In MHP-based optoelectronics, vdW lamination strategies are categorized according to component dimensionality: one-dimensional/three-dimensional (1D/3D) lamination using nanowires or carbon nanotubes; two-dimensional/three-dimensional (2D/3D) lamination using 2D semiconductors such as graphene and transition metal dichalcogenides (TMDCs); and three-dimensional/three-dimensional (3D/3D) lamination involving metals, semiconductors, and insulators. High-performance and stable perovskite-based devices can be achieved by carefully selecting the materials and optimizing the van der Waals lamination conditions. Finally, we summarize the recent advances in vdW lamination-based integration for perovskite optoelectronics. Critical issues that hinder further development and practical implementation of vdW lamination in MHPs are identified, and potential strategies are discussed to stimulate future research within the field.