3D Meniscus‐Guided Evaporative Assembly for Rapid Template‐Free Synthesis of Highly Crystalline Perovskite Nanowire Arrays

Abstract

Low-dimensional nanostructures of halide perovskites have been receivingextensive research interest for their superior optical, electrical, and stability characteristics over their conventional bulk counterparts. In particular, the unique surficial characteristics of well-defined 1D nanowires have shown high feasibility for high performance optoelectronic applications. The key aspect of endorsing this nanoscale form factor in practical applications lies in securing dimensional uniformity and controllability in large scales, which generally requires complicated lithographic procedures. In this work, a simple, rapid, and widely applicable strategy for the direct synthesis and printing of wellaligned nanowire arrays on a large scale is demonstrated. By employing blade coating methods with sophisticatedly controlled stick-slip motions, periodically resolved transverse 3D meniscus enables uniform directional growth of highly crystalline CsPbI 3 nanowires without the need for templates. A systematic investigation of morphological evolutions with respect to kinetic processing variables is conducted, along with a comprehensive suite of structural and optical analyses for the synthesized nanowire arrays. A single nanowire photodetector is employed to demonstrate the superiority and applicability of the fabrication strategy. Finally, a 2D image recognition is demonstrated by using an array of photodetectors fabricated via a fast (<2 min) direct printing of nanowire arrays on wafers.

Microstructures Formation through Liquid‐Assisted Assembly of Functional Materials for High‐Performance Electronics

“…Reproduced with permission. [62] Copyright 2022, John Wiley and Sons. c) Conceptualization of the horizontal strip formation.…”

“…The conventional stick-slip motion for nanomaterial assembly typically results in 1D assemblies that are oriented parallel to the TCL, with the length of the 1D structure dependent on the geometrical shape of the blade (Figure 3a). A modified motion-controlled blade coating method that can produce stripes perpendicular to the TCL (Figure 3b) was reported by Kim et al [62] This modified method comprises two steps of nucleation and growth processes. The nucleation seed formation is guaranteed during the initial stick step, and the directional growth of nanowires is accomplished by the stable movement of the blade during the slip motion.…”

“…Reproduced with permission. [62] Copyright 2022, John Wiley and Sons. f) Schematic illustration of the image sensor relying on array-based photodetectors under different wavelengths.…”

“…Kim et al achieved image cognition arrays by directly printing nanowire arrays on pre-patterned electrodes. [62] The stick-slip motion precisely controlled the assembly process, resulting in a stable and homogenous distribution of photodetector performances. The results of image cognitive mapping showed sharp edges of mask patterns, indicating the successful construction of the image-sensing platform (Figure 16d,e).…”

“…a) Schematics of a conventional stick-slip motion for nanomaterial assembly and b) a modified stick-slip motionfor the perovskite nanowire growth. Reproduced with permission [62]. Copyright 2022, John Wiley and Sons.…”