Graphoepitaxy of Large Scale, Highly Ordered CsPbBr₃ Nanowire Array on Muscovite Mica (001) Driven by Surface Reconstructed Grooves

Abstract

Muscovite mica [KAl 2 (Si 3 Al)O 10 (OH) 2 ] is a good electrical and thermal insulator with stable physical and chemical properties. [1] As a layered crystal, bulk muscovite can be compressed into 2D nanosheets by mechanical or chemical exfoliation, which has sparked attention since the emergence of graphene. Few-layered muscovite exhibits useful physical properties, such as excellent proton and electrical conductivity, efficient cations exchange for pollutants, etc. [2-5] Moreover, due to weak interlayer interactions, naturally cleaved muscovite (001) can be easily achieved without active surface dangling bonds. Thus, as a consequence of the atomic-level flatness, it has become one of the most frequently used substrates in van der Waals epitaxial technologies. A variety of emergent materials, including II-VI/III-V semiconductors, [6-9] transition metal dichalcogenides, [10] metal halide perovskites, [11-19] topological insulators, [20] and oxides, [21] were grown on muscovite (001) in the past decades. These single crystals exhibited superior optoelectronic and electronic properties, compared to those grown on nonlayered substrates. In most of these reports, a quasi-hexagonal lattice was considered inherent from the geometry of the topmost (Si, Al)-O aluminosilicate tetrahedra layer, leading to the tridirection epitaxy of the as-deposited crystals along the [100], [110], and [101] directions. [11,14,20,21] However, the latest spectroscopy studies on the surface lattice of muscovite (001) showed that the aluminosilicate tetrahedra were distorted and the surface trigonal symmetry was partially broken. [22] The surface reconstruction may not only provide a powerful platform to fabricate large scale anisotropic structures as demonstrated in organic molecules and crystals, but also can be applied to anisotropic few-layered muscovite devices. [2,4,21] Metal halide perovskites combine the advantages of both organic and inorganic semiconductors, such as ease of fabrication, large exciton binding energy, and low trapping states, to achieve high performance electronic and optical devices. [23-25] Among the perovskite family, all-inorganic CsPbBr 3 has drawn wide attention due to its excellent photoluminescence (PL) quantum yield with environmental stability. [26-32] Especially, 1D nanowire (NW) of CsPbBr 3 has been considered as

Oriented Halide Perovskite Nanostructures and Thin Films for Optoelectronics

“…The mica (001) surface can be further modified by removing the interlayer potassium to induce a distortion of the aluminosilicate tetrahedra, resulting in the breaking of the intrinsic quasi-hexagonal symmetry and the making of groove bunches along the [100] direction. As reported by Li et al, such grooves enabled vapor-phase graphoepitaxial growth on the millimeter-scale, unidirectional single-crystalline CsPbBr 3 NW arrays …”

“…As reported by Li et al, such grooves enabled vapor-phase graphoepitaxial growth on the millimeterscale, unidirectional single-crystalline CsPbBr 3 NW arrays. 125 2.4.2. Vapor-Phase Nonepitaxy Growth.…”

Vertically Aligned CsPbBr3 Nanowire Arrays with Template-Induced Crystal Phase Transition and Stability

“… 22 − 24 However, most of these studies used unprotected in-plane NWs with horizontal alignment. 12 , 19 − 28 A few studies have investigated vertically aligned MHP NW arrays, which have been proven to have high light extraction capability for LED devices 14 , 29 and high resolution for pixel image sensors. 30 So far, studies on vertically aligned CsPbBr 3 NW arrays are limited.…”

“…The growth of CsPbBr 3 NWs and their various optoelectronic applications have been explored, e.g., for lasing, multicolor displays, control of emission anisotropy, and light guiding as well as photodetection. − However, most of these studies used unprotected in-plane NWs with horizontal alignment. ,− A few studies have investigated vertically aligned MHP NW arrays, which have been proven to have high light extraction capability for LED devices , and high resolution for pixel image sensors . So far, studies on vertically aligned CsPbBr 3 NW arrays are limited.…”

Polarized Photoluminescence from Lead Halide Perovskites

“…Zhang et al reported the synthesis of aligned CsPbBr 3 and CsPbCl 3 nanowires on mica substrates using a vapor-phase van der Waals incommensurate epitaxial method. [67,110] The low lattice mismatch between the exposure surface of CsPbX 3 (Br/ Cl) and mica making the nanowires well aligning along one direction related to mica substrate, as shown in Figure 10a. The photoluminescence anisotropy in as-prepared CsPbBr 3 nanowires was examined under linearly polarized laser excitation, as shown in Figure 10b.…”