Heyou Zhang

University of Melbourne | MSD · School of Chemistry

Using surface‐templated electrophoretic deposition, arrays of polymer beads (photonic units) incorporating photo‐switchable DAE molecules are created, which can be reversibly and individually switched between high and low emission states by direct photo‐excitation, without any energy or electron transfer processes within the molecular system. The m...

Using surface-templated electrophoretic deposition, we have created arrays of polymer beads (photonic units) incorporating photo-switchable DAE molecules, which can be reversibly and individually switched between high and low emission states by direct photo-excitation, without any energy or electron transfer processes within the molecular system. T...

Cu2ZnSn(S,Se)4 (CZTSSe) absorber layers are realized. The single‐layer CZTSSe absorber exhibits reduced carrier recombination, enhanced carrier density and increased work function. The improved back contact and absorber layer enables 11.1% power‐conversion‐efficiency to be achieved. A key challenge facing CZTS and other chalcogenide‐based photovolt...

Controlled nanocrystal assembly is a pre‐requisite for incorporation of these materials into solid state devices. Many assembly methods have been investigated which target precise nanocrystal positioning, high process controllability, scalability, and universality. However, most methods are unable to achieve all of these goals. Here, surface templa...

Using simultaneous, in situ optical spectroscopy and time-resolved, small-angle X-ray scattering (SAXS), we have directly monitored the seeded growth of nearly monodisperse gold nanorods using hydroquinone as the reductant. Growth of the rods is much slower than with the ascorbate ion, allowing the rate of growth along both the longitudinal and tra...

Although many nanoscale materials such as quantum dots and metallic nanocrystals exhibit size dependent optical properties, it has been difficult to incorporate them into optical or electronic devices because there are currently no methods for precise, large-scale deposition of single nanocrystals. Of particular interest is the need to control the...

Unusual structural colors are demonstrated in thin‐film coatings due to a combination of optical interference and light scattering effects. These vivid colors are concealed under ambient illumination but can be observed when light is reflected from the film surface. The origin of the effect is explored computationally and it is shown that, in thin‐...

In article number 1904551, Paul Mulvaney and co‐workers review the development of single nanocrystal fabrication and assembly. Directed assembly methods rely on an external force to drive pre‐synthesized nanomaterials onto a templated surface. These methods offer nanometer spatial resolution for a wide range of materials and they also offer scalabi...

Anti‐reflective surfaces are of great interest for optical devices, sensing, photovoltaics, and photocatalysis. However, most of the anti‐reflective surfaces lack in situ tunability of the extinction with respect to wavelength. This communication demonstrates a tunable anti‐reflective surface based on colloidal particles comprising a metal core wit...

To realize the full potential of nanocrystals in nanotechnology, it is necessary to integrate single nanocrystals into addressable structures; for example, arrays and periodic lattices. The current methods for achieving this are reviewed. It is shown that a combination of top‐down lithography techniques with directed assembly offers a platform for...

Stimuli‐responsive optical etalons are an exciting class of next‐generation sensors because they are scalable, cost‐effective and offer tunability of their optical response across the entire UV–vis–NIR wavelength range. In this study, double‐network cellulose hydrogels are used as a soft, responsive medium and are incorporated into Fabry–Pérot opti...

Highly active Fe-Nx sites that effectively improve the performance of non-precious metal electrocatalysts for oxygen reduction reactions (ORRs) are desirable. Herein, we propose a strategy for introducing a carbon template into a melamine/Fe-salt mixture to inductively generate highly active Fe-Nx sites for ORR. Using ⁵⁷Fe Mössbauer spectroscopy, X...

A major goal of nanotechnology is the assembly of nanoscale building blocks into functional optical, electrical or chemical devices. Many of these applications depend on an ability to optically or electrically address single nanoparticles. However, positioning large numbers of single nanocrystals with nanometre precision on a substrate for integrat...

Assembly of nanoscale materials into arbitrary, organized structures remains a major challenge in nanotechnology. Herein, we report a general method for creating 2D structures by combining top-down lithography with bottom-up chemical assembly. Under optimal conditions, assembly of gold nanoparticles was achieved in less than 30 minutes. Single gold...

We describe the fabrication of large area arrays of single nanoparticles using electrophoretic deposition.

Plasmon-mediated processes provide unique opportunities for selective photocatalysis, photovoltaics, and electrochemistry. Determining the influence of particle heterogeneity is an unsolved problem because often such processes introduce irreversible changes to the nano-catalysts and/or their surroundings. The challenge lies in monitoring heterogene...

One-pot microwave conjugation results in a polymerized iron-phthalocyanine (pFePc) which exhibits extremely high ORR performance,, showing activity much better than that of the FePc monomer and 20 wt % Pt/C, and similar to that of the 60 wt % Pt/C under the same catalyst loading. Furthermore, we proposed an edge-closing strategy to significantly en...

Single plasmonic nanoparticles can potentially serve as optical sensors for detecting local refractive index changes. However, simultaneous monitoring of the scattering spectra from multiple nanoparticles is not practical. Here we perform potential-scanning localized surface plasmon resonance (LSPR) sensing. Gold nanorods are immobilized on an ITO...

A facile method for the fabrication of inorganic hollow materials from cuprammonium cellulose composite filaments based on fast pyrolysis has been developed. Unlike Ostwald ripening, approaches based on the Kirkendall effect, and other template methods, this process yielded hollow materials within 100?s. The heterogeneous structure of the cellulose...

A facile method for the fabrication of inorganic hollow materials from cuprammonium cellulose composite filaments based on fast pyrolysis has been developed. Unlike Ostwald ripening, approaches based on the Kirkendall effect, and other template methods, this process yielded hollow materials within 100?s. The heterogeneous structure of the cellulose...

Atomic force microscope (AFM) users often calibrate the spring constants of cantilevers using functionality built into individual instruments. This is performed without reference to a global standard, which hinders robust comparison of force measurements reported by different laboratories. In this article, we describe a virtual instrument (an inter...

Atomic force microscope (AFM) users often calibrate the spring constants of cantilevers using functionality built into individual instruments. This is performed without reference to a global standard, which hinders robust comparison of force measurements reported by different laboratories. In this article, we describe a virtual instrument (an inter...