Zhandong Huang

Nanoparticle Based Curve Arrays for Multirecognition Flexible Electronics.

Assembly of nanoparticles into controllable micro or nanocurve circuits by a feasible strategy is demonstrated. The curves, with various tortuosity morphologies, have tunable resistive strain sensitivity, which can be integrated into a multi-analysis flexible sensor. The curve-based sensor can run complicated facial expression recognition, and may contribute practical applications on auxiliary apparatus for skin micromotion manipulation for paraplegics.

A general patterning approach by manipulating the evolution of two-dimensional liquid foams

The evolution of gas-liquid foams has been an attractive topic for more than half a century. However, it remains a challenge to manipulate the evolution of foams, which restricts the development of porous materials with excellent mechanical, thermal, catalytic, electrical or acoustic properties. Here we report a strategy to manipulate the evolution of two-dimensional (2D) liquid foams with a micropatterned surface. We demonstrate that 2D liquid foams can evolve beyond Ostwald ripening (large bubbles always consuming smaller ones). By varying the arrangement of pillars on the surface, we have prepared various patterns of foams in which the size, shape and position of the bubbles can be precisely controlled. Furthermore, these patterned bubbles can serve as a template for the assembly of functional materials, such as nanoparticles and conductive polymers, into desired 2D networks with nanoscale resolution. This methodology provides new insights in controlling curvature-driven evolution and opens a general route for the assembly of functional materials.

Wearable Large‐Scale Perovskite Solar‐Power Source via Nanocellular Scaffold

Dramatic advances in perovskite solar cells (PSCs) and the blossoming of wearable electronics have triggered tremendous demands for flexible solar-power sources. However, the fracturing of functional crystalline films and transmittance wastage from flexible substrates are critical challenges to approaching the high-performance PSCs with flexural endurance. In this work, a nanocellular scaffold is introduced to architect a mechanics buffer layer and optics resonant cavity. The nanocellular scaffold releases mechanical stresses during flexural experiences and significantly improves the crystalline quality of the perovskite films. The nanocellular optics resonant cavity optimizes light harvesting and charge transportation of devices. More importantly, these flexible PSCs, which demonstrate excellent performance and mechanical stability, are practically fabricated in modules as a wearable solar-power source. A power conversion efficiency of 12.32% for a flexible large-scale device (polyethylene terephthalate substrate, indium tin oxide-free, 1.01 cm2 ) is achieved. This ingenious flexible structure will enable a new approach for development of wearable electronics.

Swarm Intelligence-Inspired Spontaneous Fabrication of Optimal Interconnect at the Micro/Nanoscale

A spontaneous process is demonstrated to assemble nanoparticles into an optimal interconnect, as natural systems spontaneously figure out the shortest path. The optimal interconnect leads to a 65.9% decrease in electromagnetic interference, a 17.1% decrease in delay, and a 24.5% decrease in energy-delay. It will be of great significance for interconnect fabrication of versatile electronic circuits.

Synthesis and crystal structures of copper(II) and silver(I) complexes of a biphenyl-bridged bipyrazolyl ligand

A semirigid bipyrazolyl ligand, 4,4′-bis[(3″,5″-diethyl-1H-pyrazol-4″-yl)methylene)]-1,1′-biphenyl (H2L), and four of its Ag(I) and Cu(II) complexes have been prepared and structurally characterized. X-ray analysis demonstrates that the Ag(I) complexes are dinuclear molecular rectangle, while the Cu(II) complexes display a twisted rectangular structure. Two different conformations, namely cis and trans, have been observed for this bipyrazolyl ligand.

A general printing approach for scalable growth of perovskite single-crystal films

A seed printing method is developed for controllably producing perovskite single-crystal films with high yield. Perovskite single-crystal films, which exhibit exceptionally low trap density and nearly perfect translational symmetry, are believed to achieve the highest performance of perovskite-based optoelectronic devices. However, fabrication of these perovskite single-crystal films is quite difficult because of the uncontrollable nucleation caused by the rapid reaction of two perovskite precursors. We report a facile seed printing approach to selectively create millimeter-sized perovskite single-crystal films with controlled thickness and high yield. We show that perovskite single-crystal films can be perfectly transferred to almost arbitrary substrates through the printing process. The as-grown perovskite single-crystal films have excellent crystalline quality and morphology. We further demonstrate that perovskite single-crystal films can be directly printed for scalable fabrication of photodetectors and effective image sensors. This strategy allows high-yield fabrication of large perovskite single-crystal films for functional devices and may extend to other solution-processed materials for wide applications.

A 3D Self-Shaping Strategy for Nanoresolution Multicomponent Architectures

3D printing or fabrication pursues the essential surface behavior manipulation of droplets or a liquid for rapidly and precisely constructing 3D multimaterial architectures. Further development of 3D fabrication desires a self-shaping strategy that can heterogeneously integrate functional materials with disparate electrical or optical properties. Here, a 3D liquid self-shaping strategy is reported for rapidly patterning materials over a series of compositions and accurately achieving micro- and nanoscale structures. The predesigned template selectively pins the droplet, and the surface energy minimization drives the self-shaping processing. The as-prepared 3D circuits assembled by silver nanoparticles carry a current of 208-448 µA at 0.01 V impressed voltage, while the 3D architectures achieved by two different quantum dots show noninterfering optical properties with feature resolution below 3 µm. This strategy can facilely fabricate micro-nanogeometric patterns without a modeling program, which will be of great significance for the development of 3D functional devices.

Synthesis and Structures of Silver(I) Adducts with 4-Amino-3,5-diisobutyl-4H-1,2,4-triazole: The Identification of a New Type of Ag3tz6 Cluster

Reactions of silver(I) salts with 4-amino-3,5-diisobutyl-4H-1,2,4-triazole (4-NH2-3,5-iBu2-tz) or 4-amino-3,5-dibutyl-4H-1,2,4-triazole (4-NH2-3,5-Bu2-tz) yielded five new adducts, namely, [Ag2(4-NH2-3,5-iBu2-tz)2(NO3)2] (1), [Ag3(4-NH2-3,5-iBu2-tz)6](SO3CF3)3 (2), [Ag3(4-NH2-3,5-iBu2-tz)6](ClO4)3 (3), [Ag4(4-NH2-3,5-Bu2-tz)6](ClO4)4 (4) and [Ag4(4-NH2-3,5-Bu2-tz)6](CF3SO3)4 (5). X-ray analyses have been done on the first four adducts, showing that 1 and 4 adopt previously observed Ag2tz2 and Ag4tz6-a cluster structures, respectively; 2 and 3, on the other hand, contain an unprecedented Ag3tz6 cluster, which is closely related to Ag4tz6–a cluster by removal of one Ag atom from the latter. The formation of Ag3tz6 cluster other than the expected Ag4tz6 cluster in 2 and 3 has been tentatively attributed to the steric effect of isobutyl groups.

Gas/liquid interfacial manipulation by electrostatic inducing for nano-resolution printed circuits

A critical requirement for highly conductive metallic printing circuits is to obtain consecutive and high-resolution printed patterns. However, the aggregation or assembly of metallic nanocrystals in solution is usually random, which perplexes the consecutiveness and resolution of the printed circuits. In this study, we prepared consecutive nano-resolution circuits by gas/liquid interfacial manipulation. Consecutive gas/liquid interfaces were achieved by electrostatic inducing of a cationic metal ink using anionic surfactant onto the gas/liquid interface to form continuous patterns. Gas/liquid interfacial morphology was manipulated by gas/liquid/solid three phase contact line (TCL); Through controlling TCL sliding on different surfaces, submicron or nano-resolution circuits were fabricated, which showed excellent conductivity. This facile strategy showed significant potential for use in wearable electronics and high-resolution electronic circuits.

Synthesis and Crystal Structures of Copper(II), Zinc(II), Lead(II) and Cadmium(II) Tetrazole-5-carboxylate Complexes Generated via in situ Hydrolysis Reaction

Four metal complexes, namely [Cu2(ttzCOO)2(H2O)4]・4H2O (1), [Zn2(ttzCOO)2(H2O)6]・2H2O (2), [Pb(ttzCOO)(H2O)2]n (3), and {[Cd(ttzCOO)(H2O)]・1/2H2O}n (4), where ttzCOO2− = tetrazole-5-carboxylate dianion, have been prepared by the reaction of the sodium salt of 1Htetrazole- 5-carboxylic acid ethyl ester in aqueous methanolic solution at room temperature with CuCl2, ZnI2, Pb(NO3)2, or Cd(NO3)2, respectively. The compounds were characterized by elemental analysis, IR spectroscopy, TG-DSC analysis and single-crystal X-ray diffraction. While 1 and 2 are structurally similar dinuclear complexes, 3 and 4 exhibit a 1D chain structure and a 3D polymeric framework, respectively. Graphical Abstract Synthesis and Crystal Structures of Copper(II), Zinc(II), Lead(II) and Cadmium(II) Tetrazole-5-carboxylate Complexes Generated via in situ Hydrolysis Reaction