3D Printing of Vertical Heterostructures of Two Dimensional Halide Perovskites

The integration of different materials into heterostructures allows for the manipulation of interfaces and electronic structures, playing a crucial role in various modern electronics and optoelectronics applications, such as solar cells, light-emitting diodes, lasers, self-powered photodetectors, transistors, and large-scale electronic circuits^1-3. Two-dimensional (2D) halide perovskites have gained significant attention due to their superior optoelectronic properties and high stability, making them promising candidates for next-generation multifunctional devices^4,5. The heterojunctions formed by 2D halide perovskites exhibit high tolerance to lattice mismatch and low intrinsic anionic diffusion at the interface, thanks to the presence of the organic layer in the 2D quantum well, which enhance their stability and performance in optoelectronic integrated device⁶. However, achieving controllable integration of 2D perovskites remains a challenge due to their mobile and fragile crystal lattices⁷. solution and gas-solid phase intercalation have been reported for fabricating 2D perovskite-based lateral and vertical heterostructures^8,9.Nevertheless, these methods suffer from limitations, including a lack of scalability and limited control over the morphology of the resulting heterostructures, which hinders large-scale production and integration of 2D perovskite nanowire heterostructures into practical devices. In this work, we propose a novel approach for fabricating freestanding layer perovskite nanowire heterostructures using a 3D printing method. This level of control ensures uniformity and reproducibility, facilitating the deterministic fabrication of arbitrary vertical heterostructures and multi-heterostructures using 2D perovskites. Our printed heterojunction nanowires showed an excellent stability with suppressed anionic diffusion at the interface.By offering greater structural degrees of freedom, our approach allows for the precise definition of the electronic structures of the heterojunctions.<br/><br/><b>Reference</b><br/>1. Y. Liu<i> et al.</i>, Van der Waals heterostructures and devices. <i>Nature Reviews Materials</i> <b>1</b>, (2016).<br/>2. Y. Liu, Y. Huang, X. Duan, Van der Waals integration before and beyond two-dimensional materials. <i>Nature</i> <b>567</b>, 323-333 (2019).<br/>3. A. Castellanos-Gomez<i> et al.</i>, Van der Waals heterostructures. <i>Nature Reviews Methods Primers</i> <b>2</b>, (2022).<br/>4. K. Leng, W. Fu, Y. P. Liu, M. Chhowalla, K. P. Loh, From bulk to molecularly thin hybrid perovskites. <i>Nature Reviews Materials</i> <b>5</b>, 482-500 (2020).<br/>5. J. C. Blancon, J. Even, C. C. Stoumpos, M. G. Kanatzidis, A. D. Mohite, Semiconductor physics of organic-inorganic 2D halide perovskites. <i>Nat Nanotechnol</i> <b>15</b>, 969-985 (2020).<br/>6. Akriti<i> et al.</i>, Layer-by-layer anionic diffusion in two-dimensional halide perovskite vertical heterostructures. <i>Nat Nanotechnol</i> <b>16</b>, 584-591 (2021).<br/>7. J. Chen<i> et al.</i>, Oriented Halide Perovskite Nanostructures and Thin Films for Optoelectronics. <i>Chem Rev</i>, (2021).<br/>8. E. Shi<i> et al.</i>, Two-dimensional halide perovskite lateral epitaxial heterostructures. <i>Nature</i> <b>580</b>, 614-620 (2020).<br/>9. D. Pan<i> et al.</i>, Deterministic fabrication of arbitrary vertical heterostructures of two-dimensional Ruddlesden-Popper halide perovskites. <i>Nat Nanotechnol</i> <b>16</b>, 159-165 (2021).