Daping Chu

Inkjet-printed graphene electronics.

We demonstrate inkjet printing as a viable method for large-area fabrication of graphene devices. We produce a graphene-based ink by liquid phase exfoliation of graphite in N-methylpyrrolidone. We use it to print thin-film transistors, with mobilities up to ∼95 cm(2) V(-1) s(-1), as well as transparent and conductive patterns, with ∼80% transmittance and ∼30 kΩ/□ sheet resistance. This paves the way to all-printed, flexible, and transparent graphene devices on arbitrary substrates.

Flexible Electronics: The Next Ubiquitous Platform

Thin-film electronics in its myriad forms has underpinned much of the technological innovation in the fields of displays, sensors, and energy conversion over the past four decades. This technology also forms the basis of flexible electronics. Here we review the current status of flexible electronics and attempt to predict the future promise of these pervading technologies in healthcare, environmental monitoring, displays and human-machine interactivity, energy conversion, management and storage, and communication and wireless networks.

The Applications and Technology of Phase-Only Liquid Crystal on Silicon Devices

An introduction to the technology of liquid crystal on silicon (LCOS) devices leads on to a discussion of the application areas which have been and are being opened up by the development of phase-only devices.

High emission current density, vertically aligned carbon nanotube mesh, field emitter array

A vertically aligned carbon nanotube mesh emitter array has been fabricated and tested, giving a current density of up to 1.5 A/cm2, and a threshold field of 1.5 V/μm for a current density 1 mA/cm2. Low temperature carbon nanotube growth is used to fabricate the carbon nanotube mesh emitter arrays significantly reducing the cost of the fabrication of large area electron emitters. This system exhibits ultralong lifetime.

Atomic Layer Deposition of ZnO on Multi-walled Carbon Nanotubes and Its Use for Synthesis of CNT–ZnO Heterostructures

In this article, direct coating of ZnO on PECVD-grown multi-walled carbon nanotubes (MWCNTs) is achieved using atomic layer deposition (ALD). Transmission electron microscopy investigation shows that the deposited ZnO shell is continuous and uniform, in contrast to the previously reported particle morphology. The ZnO layer has a good crystalline quality as indicated by Raman and photoluminescence (PL) measurements. We also show that such ZnO layer can be used as seed layer for subsequent hydrothermal growth of ZnO nanorods, resulting in branched CNT–inorganic hybrid nanostructures. Potentially, this method can also apply to the fabrication of ZnO-based hybrid nanostructures on other carbon nanomaterials.

Zinc oxide nanowire networks for macroelectronic devices

Zinc oxide (ZnO) nanowire networks have been proposed as an alternative to organic and amorphous semiconductors for plastic electronics. Although the mobility of the ZnO networks is lower than that of individual nanowires, they offer the advantages of high transparency and flexibility. A major drawback of using individual nanowires in nano or microelectronic applications is the lack of a manufacturable process to precisely assemble nanowires into small devices. The use of ZnO networks avoid this issue for relatively large area macroelectronic devices since the devices exhibit the average properties of a large number of random individual nanowires. In this work, we have deposited uniform ZnO thin films using an easy, scalable, stamping method and characterized their electronic and optoelectronic properties. We have also demonstrated the use of ZnO networks as an active material in thin film transistors where mobility values in excess of 20 cm2/Vs has been achieved. The results presented here simply reveal the potential use of inorganic nanowires for optoelectronic devices.

Investigations into local piezoelectric properties by atomic force microscopy

We describe nanoscale characterization of sol-gel produced ferroelectric thin films of lead–zirconate–titanate. We have performed quantitative localized measurements of surface polarization charge density using atomic force microscopy techniques in conjunction with electric field calculations. We show that domains with radii of 40 nm may by written and subsequently characterized, and we analyze the dependence of domain size on write voltage and write time, and show that surface contaminants influence the formation of domains.

Dopant spatial distributions: Sample-independent response function and maximum-entropy reconstruction

We demonstrate the use of maximum entropy based deconvolution to reconstruct boron spatial distribution from the secondary ion mass spectrometry (SIMS) depth profiles on a system of variously spaced boron

Stable, self-ballasting field emission from zinc oxide nanowires grown on an array of vertically aligned carbon nanofibers

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Improved layer-based method for rapid hologram generation and real-time interactive holographic display applications.

-layers grown in silicon. Sample independent response functions are obtained using a new method which reduces the danger of incorporating real sample behaviour in the response. Although the original profiles of different primary ion energies appear quite differently, the reconstructed distributions agree well with each other. The depth resolution in the reconstructed data is increased significantly and segregation of boron at the near surface side of the