Amplifying Surface Energy Difference toward Anisotropic Growth of All‐Inorganic Perovskite Single‐Crystal Wires for Highly Sensitive Photodetector

Abstract

It is a great challenge to directly grow super long all‐inorganic perovskite monocrystalline wires due to the weak surface energy difference among the low index facets. Here, a one‐pot solution process to grow the aspect ratio over 105 of monocrystalline CsPbBr3 perovskite wires (PWs) and yield up to 70% is reported. A chemical potential dependent surface energy difference amplification strategy is proposed to regulate the surface energy of growing and grown surfaces accordingly to the anisotropic growth of CsPbBr3. The anisotropic growth of wires is derived from the regulation of anti‐solvent diffusion kinetic and the mass transfer kinetic control of the metal halide salts. This experiment demonstrates a 50 times amplification of surface energy difference. As‐produced PWs present a high photodetection responsivity up to 4923 A W−1, external quantum efficiency exceeding 13 784%, and detectivity over 3.6 × 1013 Jones. This work not only reveals the mechanism of surface energy dominated anisotropic growth for CsPbBr3 PWs, but also elucidates the important role of kinetics regulation during the growth process, which may open a new window for the low‐dimensional crystal growth of ionic compounds.

Free-Standing Metal Halide Perovskite Nanowire Arrays with Blue-Green Heterostructures

“…Chen et al also reported an increased difference in surface energies between (110) and (001) planes for growing CsPbBr 3 nanowires. 17 …”

“…Chen et al also reported an increased difference in surface energies between (110) and (001) planes for growing CsPbBr 3 nanowires. 17 According to the above analysis, the proposed growth mechanism is shown schematically in Figure 3g: The nanowires first nucleate inside the pores, since the AAO nanopores have ample surface area for heterogeneous nucleation. 21 The nanowires preferentially nucleate with the (001) planes orthogonal to the pores, that is, with the (110) side facets parallel to the AAO pore walls, presumably because (110) has the lowest solid−solid interfacial energy.…”

“… 7 − 11 However, the growth of free-standing vertically aligned MHP nanowire arrays is difficult. Compared with the numerous studies on growth of horizontal MHP nanowire arrays, 2 , 12 − 17 there are only a few reports of vertically aligned nanowire arrays, and those mostly concern nanowires physically confined inside various templates such as anodized aluminum oxide (AAO). 18 − 22 A few studies have reported free-standing MHP nanowires by solution extrusion 23 and vapor–liquid–solid 24 methods, but the alignment of the obtained NWs was not satisfactory.…”

“…For example, free-standing vertically aligned nanowires of Si, ZnO, GaAs, and InP have achieved excellent performance in various optoelectronic fields. − However, the growth of free-standing vertically aligned MHP nanowire arrays is difficult. Compared with the numerous studies on growth of horizontal MHP nanowire arrays, ,− there are only a few reports of vertically aligned nanowire arrays, and those mostly concern nanowires physically confined inside various templates such as anodized aluminum oxide (AAO). − A few studies have reported free-standing MHP nanowires by solution extrusion and vapor–liquid–solid methods, but the alignment of the obtained NWs was not satisfactory. The solution extrusion method works only when the precursor can form an intermediate phase, while the vapor–liquid–solid growth needs the assistance of a metal catalyst and high temperature .…”

Antisolvent-Processed One-Dimensional Ternary Rubidium Copper Bromine Microwires for Sensitive and Flexible Ultraviolet Photodetectors

“…This is easy to understand because a higher concentration of precursors can enable a more sufficient growth of products and a larger diameter of MWs. In our case, the growth of Rb 2 CuBr 3 MWs is very similar to that of CsPbBr 3 perovskite wires, 47 and the mechanism can be interpreted in this way: Owing to the 1D chain structure of orthorhombic Rb 2 CuBr 3 , it tends to grow into a wire morphology. Although a large concentration of liquid precursors increases the growth rate of microwires in the direction perpendicular to the wire, it is still much lower than the growth rate along the wire.…”