1D Carbon Nanotube@Perovskite Core-Shell van der Waals Heterostructures

Perovskite is an emerging material with immense potential in the field of optoelectronics. One-dimensional (1D) perovskite nanowires are crucial building blocks for the development of optoelectronic devices. However, producing perovskite nanowires with high quality and controlled alignment is challenging. In this study, we present a novel approach for the direct epitaxial growth of perovskite on oriented carbon nanotube (CNT) templates through a chemical vapor deposition method. The strategy involves three steps, growth of ultra-long CNT templates, deposition of inorganic precursor lead iodide (PbI₂), and deposition of organic precursor methylammonium iodide (MAI). Our research delved into the deposition processes of PbI₂ and MAI, and proposed a layer plus island growth mechanism to interpret the experimental observations. Leveraging the aligned long CNTs as 1D templates, we successfully grew CNT@perovskite core-shell heterostructure with a high aspect ratio (>10⁴) to withstand large deformation. Furthermore, the obtained 1D heterostructure can be precisely manipulated and transferred, facilitating the preparation of microscale flexible devices. For proof of concept, we fabricated a photodetector based on an individual CNT@methylammonium lead iodide heterostructure, whose highest photoresponsivity is up to 173.9 A W^-1 under 532 nm laser irradiation. This work provides a new approach to constructing 1D hetero-nanostructure and may inspire the design of novel flexible nanophotodetectors.