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Supplementary Figure from Inhibiting Type I Arginine Methyltransferase Activity Promotes T Cell–Mediated Antitumor Immune Responses

Supplementary Table from Inhibiting Type I Arginine Methyltransferase Activity Promotes T Cell–Mediated Antitumor Immune Responses

Protein arginine methyltransferases (PRMT) are a widely expressed class of enzymes responsible for catalyzing arginine methylation on numerous protein substrates. Among them, type I PRMTs are responsible for generating asymmetric dimethylarginine. By controlling multiple basic cellular processes, such as DNA damage responses, transcriptional regulation, and mRNA splicing, type I PRMTs contribute to cancer initiation and progression. A type I PRMT inhibitor, GSK3368715, has been developed and has entered clinical trials for solid and hematologic malignancies. Although type I PRMTs have been reported to play roles in modulating immune cell function, the immunologic role of tumor-intrinsic pathways controlled by type I PRMTs remains uncharacterized. Here, our The Cancer Genome Atlas dataset analysis revealed that expression of type I PRMTs associated with poor clinical response and decreased immune infiltration in patients with melanoma. In cancer cell lines, inhibition of type I PRMTs induced an IFN gene signature, amplified responses to IFN and innate immune signaling, and decreased expression of the immunosuppressive cytokine VEGF. In immunocompetent mouse tumor models, including a model of T-cell exclusion that represents a common mechanism of anti–programmed cell death protein 1 (PD-1) resistance in humans, type I PRMT inhibition increased T-cell infiltration, produced durable responses dependent on CD8+ T cells, and enhanced efficacy of anti–PD-1 therapy. These data indicate that type I PRMT inhibition exhibits immunomodulatory properties and synergizes with immune checkpoint blockade (ICB) to induce durable antitumor responses in a T cell–dependent manner, suggesting that type I PRMT inhibition can potentiate an antitumor immunity in refractory settings.

Protein arginine methyltransferases (PRMT) are a widely expressed class of enzymes responsible for catalyzing arginine methylation on numerous protein substrates. Among them, type I PRMTs are responsible for generating asymmetric dimethylarginine. By controlling multiple basic cellular processes, such as DNA damage responses, transcriptional regulation, and mRNA splicing, type I PRMTs contribute to cancer initiation and progression. A type I PRMT inhibitor, GSK3368715, has been developed and has entered clinical trials for solid and hematologic malignancies. Although type I PRMTs have been reported to play roles in modulating immune cell function, the immunologic role of tumor-intrinsic pathways controlled by type I PRMTs remains uncharacterized. Here, our The Cancer Genome Atlas dataset analysis revealed that expression of type I PRMTs associated with poor clinical response and decreased immune infiltration in patients with melanoma. In cancer cell lines, inhibition of type I PRMTs induced an IFN gene signature, amplified responses to IFN and innate immune signaling, and decreased expression of the immunosuppressive cytokine VEGF. In immunocompetent mouse tumor models, including a model of T-cell exclusion that represents a common mechanism of anti–programmed cell death protein 1 (PD-1) resistance in humans, type I PRMT inhibition increased T-cell infiltration, produced durable responses dependent on CD8+ T cells, and enhanced efficacy of anti–PD-1 therapy. These data indicate that type I PRMT inhibition exhibits immunomodulatory properties and synergizes with immune checkpoint blockade (ICB) to induce durable antitumor responses in a T cell–dependent manner, suggesting that type I PRMT inhibition can potentiate an antitumor immunity in refractory settings.

Despite advances in seismology and computing, the ability to image subsurface volcanic environments is poor, limiting our understanding of the overall workings of volcanic systems. This is related to substantive structural heterogeneities which strongly scatters seismic waves obscuring the ballistic arrivals normally used in seismology for wave velocity determination. Here we address this constraint by, using a deep learning approach, a Fourier neural operator (FNO), to model and invert seismic signals in volcanic settings. The FNO is trained using 40,000+ simulations of elastic wave propagation through complex volcano models, and includes the full scattered wavefield. Once trained, the forward network is used to predict elastic wave propagation and is shown to accurately reproduce the seismic wavefield. The FNO is also trained to predict heterogeneous velocity models given a limited set of input seismograms. It is shown to capture details of the complex velocity structure that lie far outside the ability of current methods available in volcano imagery.

Objectives: Falls and injuries are frequent in professional horseracing. However, professional jockeys spend a large part of their week in horse-related activities outside of racing such as schooli...

Amorphous TiO2 and SnO2 electron transport layers (ETLs) were deposited by low-temperature atomic layer deposition (ALD). Surface morphology and x-ray photoelectron spectroscopy (XPS) indicate uniform and pinhole free coverage of these ALD hole blocking layers. Both mesoporous and planar perovskite solar cells were fabricated based on these thin films with aperture areas of 1.04 cm2 for TiO2 and 0.09 cm2 and 0.70 cm2 for SnO2. The resulting cell performance of 18.3 % power conversion efficiency (PCE) using planar SnO2 on 0.09 cm2 and 15.3 % PCE using mesoporous TiO2 on 1.04 cm2 active areas are discussed in conjunction with the significance of growth parameters and ETL composition.

Here, as with previous work, atomic layer deposition (ALD) has been used to deposit Al2O3 on positive electrode active materials, LiCoO2, to create a protective barrier layer, suppress the high potential phase transition, and thus reduce the subsequent Co dissolution. However, in this study it was found that it also resulted in the reduction of the charge transfer resistance at the positive electrode–electrolyte interface, thus enhancing the performance of the battery. Energy-dispersive X-ray spectroscopy, in conjunction with transmission electron microscopy, shows that a discrete Al2O3 shell was not formed under the selected growth conditions and that the Al diffused into the bulk LiCoO2. The resulting active oxide material, which was significantly thicker than the nominally ALD growth rate would predict, is proposed to be of the form LiCoO2:Al with amorphous and crystalline regions depending on the Al content. The cells consisting of the modified electrodes were found to have good cycling stability and discharge capacities of ∼110 mA h g–1 (0.12 mA h cm–2) and ∼35 mA h g–1 (0.04 mA h cm–2) at 50 and 100 C, respectively.

The growth of silver doped vanadium pentoxide was performed by aerosol assisted chemical vapour deposition and found to be optimal at 450° C. Additionally, an increase in crystallinity and a change in preferred orientation of V2O5 was observed upon increasing the silver content. Silver incorporation also resulted in morphological changes in the thin films from rod to pellet-like structures. For higher silver content films the amount of incorporated charge increased and reversibility and repeatability was demonstrated for 500 cycles. Electrochemical impedance spectroscopy determined that the transfer and diffusion of Li+ ions through the cathode-electrolyte interface was assisted by silver loading, hence, enhancing the capacitive performance.

The aerosol assisted chemical vapor deposition of monoclinic vanadium pentoxide coatings was performed on fluorine doped tin dioxide coated glass substrates using vanadyl(IV) acetylacetonate at 400 °C for a range of growth periods. It was observed that the sample grown for 1 h presented the best electrochemical response in terms of the highest charge storage (30 mC cm −2 ) and the difference in transmittance in the visible and near-infrared spectral regions (27% at 650 nm and 17% at 900 nm) with a fast response time (12 s for coloration and 10 s for bleaching). The importance of achieving samples with (2 0 0) preferred orientation for the improvement of electrochromic performance is highlighted.

An atomic layer deposition process for coating a wool-synthetic fabric sample with alumina was developed. The coating efficacy was evaluated by both internal and commercial indicative flame resistance studies. It was shown that untreated samples burnt to completion on removal of the ignition source, but in the case of the treated samples, the flame on the fabric extinguished rapidly on removal of the ignition source, leaving the sample intact after the test. Thermal gravimetric analysis showed that successful fire resistance treatment was achieved by addition of alumina with less than 1% weight of the fabric. It was concluded that the atomic layer deposition coating of oxide offered significant advantages in the area of fire resistance treatment, since in addition to its effectiveness, treated fabrics exhibit a negligible increase in weight, remained flexible, breathable and did not undergo any change in color or palpable texture.

In this paper we report on the structural and electrical properties of hafnium silicate films grown by atomic layer deposition on a platinum bottom electrode. The results are compared to previously published results from our laboratory for an aluminum bottom electrode structure, with otherwise identical processing of the dielectric layer. The results demonstrate that the bottom electrode has a marked effect on both the structure and electrical properties of the resulting MIM capacitor. The previously reported films on aluminum were found to exhibit excellent electrical properties over a range of substrate materials and were consistent with hafnium silicate. In this study high resolution transmission electron microscopy (HRTEM) analysis and Raman spectroscopy indicate that on platinum the main crystalline phase is monoclinic HfO2 with a dielectric constant (k) value of ~18. Despite the crystalline nature of the HfO2 no hysteresis was observed in the capacitance voltage measurements. The scanning transmission electron microscopy (STEM) analysis also reveals the presence of nanoparticles, located primarily towards the lower platinum metal electrode at the HfO2 grain boundaries. Based on energy-dispersive x-ray spectroscopy (EDX) analysis the nanoparticles are consistent with silicon oxide inclusions.

Nanocomposite films were successfully grown by aerosol-assisted chemical vapour deposition (CVD) in a single deposition step using a mixture of indium tin neodecanoate and ligand stabilised silicon nanocrystals. Samples were analysed by HRTEM and silicon nanocrystals with a density of 1.2 × 1012 cm−2 were observed. From the reconstructed 3D tomogram, the averaged distance between the nearest nanoparticles is 8.3 nm and the 3D density of nanoparticles is 1.6 × 1018 cm−3. An animation of the 3D reconstruction is supplied in the supporting information. These data show the versatility of aerosol assisted CVD in achieving a nanocomposite with such a density of silicon nanocrystals, of carefully controlled size and shape, within a polycrystalline host matrix. Therefore, meeting the density and size distribution requirements of particle inclusion in active nanocomposites for photovoltaic structures. ITO–silicon nanocrystal nanocomposite samples were analysed by HRTEM and silicon nanocrystals with a density of 1.2 × 1012 cm−2 were observed. From the reconstructed 3D tomogram, the averaged distance between the nearest nanoparticles is 8.3 nm and the 3D density of nanoparticles is 1.6 × 1018 cm−3.

A method which combines polymer particle assembly, chemical infiltration and etching with an aerosol assisted deposition process is described for the fabrication of 3D inverse opal (10) structures with sub-micron periodicity and precision. This procedure not only overcomes limitations associated with slow, expensive micro-fabrication methods but also permits the tuning of refractive index contrast via the direct incorporation of photonically-active, preformed, tailored silicon nanostructures. It is demonstrated that this approach can be used to modify the photonic band gap (PBG) by effectively depositing/patterning optically active silicon nanocrystals (ncSi) onto the pore walls of a 3D inverse opal structure. This simple, yet effective method for preparing functional complex 3D structures has the potential to be used generically to fabricate a variety of functional porous 3D structures that could find application not only in new or improved photonic crystal (PC) devices but also in areas such as catalysis, separation, fuel cells technology, microelectronics and optoelectronics.

Novel processes were developed for fabricating silicon nanocrystals and nanocomposite materials which could be used as absorbers in third generation photovoltaic devices. A conventional high-temperature annealing technique was studied as a reference process, with some new insights in crystallisation mechanisms. Innovative methods for silicon nanocrystal synthesis at much lower temperature were demonstrated, namely chemical vapour deposition (CVD), physical vapour deposition (PVD) and aerosol-assisted CVD. Besides the advantage of low substrate temperature, these new techniques allow to fabricate silicon nanocrystals embedded in wide bandgap semiconductor host matrices, with a high density and a narrow size dispersion.

This paper presents a method for measuring the complex permittivity of a dielectric material on a dielectric/metal stack without etching the dielectric layer. A series of circular capacitor test structures were designed and fabricated. For the first time, the unwanted capacitance Cp, which is formed by the oxide layer between the bottom metal layer and the silicon substrate, was defined and systematically investigated. The technique is shown to be suitable for characterization of a lead magnesium niobate-lead titanate (PMNT) material on the complex cross sections involved in the development of a novel high-k material. An extremely high- k of 1115 (high capacitance density of 26 fF/μm2) for a PMNT metal-insulator-metal (MIM) capacitor was achieved. In addition, low leakage current density of 2 × 10-10 A/cm2 and low loss tangent were also obtained. These results clearly showed that the PMNT MIM capacitors are very promising for both decoupling and more general RF and mixed-signal applications until the year 2020, according to the International Technology Roadmap for Semiconductors (ITRS).

This paper reports on the temperature dependence of the electrical properties of high-k lead–magnesium–niobium titanate thin films processed with different compositions (with and without nanoparticles) and with different annealing temperatures (450 °C and 750 °C). These characterization results support the ongoing investigation of the material's electrical properties which are necessary before the dielectric can be used in silicon-based IC applications.

The influence of doping on the morphology, physical and electrical properties of zinc oxide produced by the sol-gel method was examined. Undoped zinc oxide was observed to form relatively porous films. Addition of an Al dopant influenced the sheet resistance, but did not result in a change in morphology, examined by atomic force microscopy when compared to undoped films. In the case of electrical measurements, undoped ZnO films were extremely resistive. A minimum dopant concentration of 2 at.%. Al was required to produce materials which were more conductive, as observed by sheet resistance measurements, which were shown to vary with annealing temperature. The versatile nature of sol-gel processing was demonstrated by selective ink-jet deposition of sol-gel droplets which were annealed to form oxide materials.

A near morphotropic phase boundary lead–magnesium–niobium titanate material system was synthesised by the sol–gel method; its thin films were deposited with or without nanoparticle (np) seeding and processed by the rapid thermal annealing. Influences of some process parameters and the np seeding on various properties of the resultant films were systematically investigated. Although no reduction in annealing temperature was achieved upon np seeding, the results indicated that nps might indeed play a role as nucleation centres during the crystallisation. All in all, the lead–magnesium–niobium titanate thin film system described here (particularly those annealed at higher temperatures) appeared to be suitable for its potential applications in wireless communication systems as ultrahigh dielectric constant e value capacitors; the unexposed film annealed at 750uC, for instance, exhibited the highest dielectric constant e (1425) with a low loss (loss tangent, y0?04) along with a strongly pronounced perovskite phase (96?5%).

This work studies the impact of adding nanoparticles to high-k PMNT (lead magnesium niobate–lead titanate, Pb(Mg0.33Nb0.67)0.65Ti0.35O3) thin films. PMNT thin films were grown on Pt(111)/TiO2/SiO2/Si substrate using a sol–gel technique. Ligand stabilised PMNT nanoparticles were added to the sol–gel material with the aim of seeding the crystallization process. The measurements show that use of nanoparticles in PMNT thin films influences the remanent polarization, coercive field and dielectric constant. These characterization results support the ongoing investigation of the material ferroelectric and electrical properties which are necessary before the novel dielectric can be used in silicon applications.

Improved material systems are of great interest in the development of two-photon polymerization techniques for the fabrication of three dimensional micro- and nano-structures. The properties of the photosensitive resin are important in the realisation of structures with submicron dimensions. In this study investigation of a custom organic resin, cross-linked by a two-photon induced process, using a femtosecond Ti:sapphire laser, is described. A structural, optical and mechanical analysis of the optimised material is presented. The influence of both material system and laser processing parameters on achievable micro-structure and size is presented as are representative structures. Parameters include: laser power, photo-initiator concentration and material composition.

Indium doped, and undoped, zinc oxide films were deposited using aerosol assisted chemical vapour deposition (AACVD) at atmospheric pressure on glass substrates. Electrical measurements ( I – V ) showed a reduction in resistivity following the addition of indium, and XRD analysis revealed an associated switch to c -axis preferred crystal orientation. The ability of the films to oxidise organic material on their surface was analysed using stearic acid as the model contaminant under ultra-violet (UV, 365 nm) irradiation. The In-doped films displayed a greater rate of organic decomposition, which we attribute to the formation of a platelet surface structure having a larger surface area than the undoped films, on which the UV generated electrons and holes may react to form active photocatalytic species. In addition we suggest that the switch to c -axis crystal orientation may reduce the electron–hole pair recombination rate at the grain boundaries, due to an improvement in crystallinity and related reduction in carrier scattering losses, leading to an increase in photocatalytic organic decomposition rate.

In comparison to ITO films prepared by chemical solution deposition on bare substrates, the use of a ZnO buffer layer and Al2O3 barrier layer has been shown to have a significant effect on morphology, measured sheet resistance and therefore resistivity. In the case of quartz substrates, ITO resistivity decreased from 9.6 x 10(-3) ohms cm to 4.3 x 10(-3) ohms cm on incorporation of a ZnO buffer layer and Al2O3 barrier layer, both grown by ALD. A change in surface morphology was observed, due to the presence of the buffer layer, however, the ZnO buffer layer was not found to influence the XRD pattern of the ITO films.

This work aimed to describe the sol-gel synthesis and preparation of a near-morphotropic phase boundary lead-magnesium-niobium titanate (PMNT) material system, and to investigate the influences of room-temperature-UV-irradiation and rapid thermal annealing (RTA) processes on the properties of its thin films. It was postulated that the use of UV-irradiation prior to thermal processing could play a role in the generation of a structural difference that would manifest itself via the formation of a higher film thickness, which was more pronounced at higher RTA temperatures The PMNT thin film system described here (particularly those annealed at higher temperatures) appeared to be potentially suitable for ultrahigh-value-capacitor applications; the unexposed film annealed at 750 °C exhibited the highest high k value (1425) with a strongly pronounced perovskite phase (97%).

Zinc oxide (ZnO) has attracted recent interest for a range of applications, including use as a transparent conductive oxide (TCO) and in gas sensor devices. This paper compares ZnO films grown using two methods designed for the production of thin films, namely sol–gel and aerosol assisted chemical vapour deposition (AACVD) for potential use in sensor and TCO applications. Materials produced by the sol–gel route were observed to be amorphous when annealed at 350 °C, but were crystalline when annealed at higher temperatures and had a relatively open grain structure when compared to the AACVD films. Electrical characterization showed that materials were highly resistive, but that their properties varied considerably when the measurements were performed in vacuum or in air. This behaviour was rapidly reversible and reproducible for room temperature measurement. In contrast materials grown by aerosol-assisted CVD were non-porous, polycrystalline and conductive. Measured electrical properties did not vary with changing measurement atmosphere. These differences are discussed in terms of the structural characterisation of the films and some comments are made regarding the suitability of both approaches for the growth of ZnO thin film sensor materials.

Both single- and multi-layer thin films of sol–gel-derived undoped and Al-doped zinc oxide material systems were fabricated for potential use in transparent conducting oxide modules. Functional properties of the resultant films were characterised comparatively. High degree of reproducibility was demonstrated for the characterised properties, with the exception of the electrical conductivity. Influences of Al doping on the characterised properties were also investigated. Al doping reduced the average crystallite size, and led to a denser and less porous morphology, and also caused an increase in transparency in the UV region. Moreover, it was shown that the electrical conductivity of this thin film system could be improved upon either the application of a forming gas process, or Al doping.

Thin films of sol–gel derived undoped and Al-doped zinc oxide material systems were fabricated for potential use in transparent conducting oxide modules. A comparative characterisation of the functional properties of the films was performed. Undoped zinc oxide thin films were obtained with desired properties. Al doping reduced the average crystallite size, and led to a denser and less porous morphology, and also caused an increase in transparency in the UV region. An improvement in electrical conductivity was achieved upon Al doping. Temperature cycling and accelerated delamination test results demonstrated the high physical reliability of the thin films of the material system obtained in this study.

In this paper, we present a low-cost rapid replication approach to fabricate ZnO and Al-doped ZnO Transparent Conductive Oxide electrode structures using both hard UV curable polyurethane acrylate and soft thermal curable polydimethylsiloxane moulds. The thin films of the ZnO and Al-ZnO sol–gel precursor solution prepared from zinc acetate monoethanolamine and isopropanol were cast into a polydimethylsiloxane or polyurethane acrylate mould containing the electrode design. For soft mould embossing, the sol–gel coated substrate and polydimethylsiloxane mould were dried under vacuum at 70 °C for 3h. While for hard mould embossing, the system was heated at 150 °C for 30 min with 100 N applying force and then demoulded at 80 °C. The formed electrode patterns can be further densified or annealed giving a stable film that retains the embossed shape. The difference of surface profile obtained by soft and hard moulding is detailed and the hard mould is shown to be more suitable for low aspect ratio conductors. And the reliability study on embossed ZnO and Al-ZnO conductive tracks prepared with hard moulds shows that the embossed structure still retains good quality.

Zinc oxide thin films were prepared using either zinc acetate dihydrate or anhydrous zinc acetate via the sol–gel method. Comparative characterisation of the crystallographical, morphological, optical/spectroscopical and electrical properties of the so-obtained films was performed. The idea of one- (in the case of the anhydrous precursor), and two- (in the other case) stage hydrolysis/condensation was postulated, which was supported by the characterisation results. The film prepared using the anhydrous precursor had a more pronounced c-axis crystal orientation preference, with a larger average crystallite size and more porous morphology. The transparency of this film was significantly lower over the UV/visible region due to its more porous morphology, which also resulted in lower intensity of the ‘near band edge emission’, and higher electrical resistivity. The overall results also suggested that anhydrous zinc acetate could be employed as a precursor for the sol–gel synthesis of zinc oxide thin films, which might have potential advantages in microelectronic and optoelectronic applications.

Fs laser-based two-photon polymerisation (2PP) has been widely reported as a means of directly writing three-dimensional nanoscale structures. Usually the voxel of a high numerical aperture microscope objective is scanned through the resin to build up the required model. In the case of high aspect ratio two-dimensional structures, such as cell scaffolds, repeated scanning is required to build up the height. The voxel shape can be substantially elongated by the inclusion of an axicon lens in the laser beam line. In this report we describe the use of a Bessel beam produced in the region beyond the focus of an objective lens when the beam has been modified in this way. A Ti:sapphire laser was used to write a range of 2D square cell structures in a Zr-loaded sol–gel system. The process was characterised, in terms of the dimensions of the polymerised Bessel region, for different processing conditions. Examples of the structures are also described.

A low cost zinc oxide embossing technique is reported as a method of fabricating structures relevant to a variety of applications. A zinc based sol–gel material was prepared from zinc acetate [Zn(C2H3O2)2], monoethanolamine [H2NC2H4OH] and isopropanol. The sol–gel was cast into a polydimethylsiloxane (PDMS) mould a track design, placed in contact with the substrate and dried under vacuum at 70 °C for 3 hours. The formed track pattern was further densified to provide a stable conductor film that retained the embossed shape. An optimum Zn sol–gel content of 0.6 M was identified. The embossed films had a transparency of greater than 83% in the visible region. The optical bandgap energy was evaluated to be 3.306 eV. The influence of ZnO sol–gel film synthesis and embossing parameters on the microstructure, morphology and optical transparency of fabricated structures is described. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

ZnO thin films were prepared on fused silica from a single spin-coating deposition of a sol–gel prepared with anhydrous zinc acetate [Zn(C 2 H 3 O 2 ) 2 ], monoethanolamine [H 2 NC 2 H 4 OH ] and isopropanol. Crystallization annealing was performed over the range 500 to 650 °C. X-ray analysis showed that thin films were preferentially orientated along the [002] c-axis direction of the crystal. The films had a transparency of greater than 85% in the visible region for sol–gels with a zinc content of up to 0.7 M and exhibited absorption edges at ∼ 378 nm. The optical band-gap energy was evaluated to be 3.298–3.306 eV. Photoluminescence showed a strong emission centered at ca. 380 nm along with a broad yellow-orange emission centered at ca. 610 nm. Single step sol–gel thin film deposition in the film thickness range from 80 nm to 350 nm was demonstrated. The effect of sol–gel zinc concentration, film thickness and crystallization temperature on film microstructure, morphology and optical transparency is detailed. A process window for single spin coating deposition of c-axis oriented ZnO discussed.

ZnO thin films were prepared on soda-lime glass from a single spin-coating deposition of a sol–gel prepared with anhydrous zinc acetate [Zn(C2H3O2)2], monoethanolamine [H2NC2H4OH] and isopropanol. The deposited films were dried at 50 and 300 °C. X-ray analysis showed that the films were amorphous. Laser annealing was performed using an excimer laser. The laser pulse repetition rate was 25 Hz with a pulse energy of 5.9 mJ, giving a fluence of 225 mJ cm−2 on the ZnO film. Typically, five laser pulses per unit area of the film were used. After laser processing, the hexagonal wurtzite phase of zinc oxide was observed from X-ray diffraction pattern analysis. The thin films had a transparency of greater than 70% in the visible region. The optical band-gap energy was 3.454 eV. Scanning electron microscopy and profilometry analysis highlighted the change in morphology that occurred as a result of laser processing. This comparative study shows that our sol–gel processing route differs significantly from ZnO sol–gel films prepared by conventional furnace annealing which requires temperatures above 450 °C for the formation of crystalline ZnO.

The fabrication of three-dimensional microstructures by two-photon polymerisation has been widely reported as a viable route to the development of photonic crystals, rotors, bridges and other complex artefacts requiring nanoscale resolution. Conventionally, single point serial writing is used to write the structures but recently multipoint beam delivery using beam division optics has been reported as a method of introducing parallel processing. In this paper we present an alternative and novel approach using an axicon lens to give profiled beam delivery. This enables complete three-dimensional annular structure fabrication without the use of scanning stages. In addition, the concept of axicon delivery is developed further to investigate three-dimensional structure as a function of axicon geometry. A Ti:sapphire laser, with wavelength 795 nm, 80 MHz repetition rate, 100 fs pulse duration and an average power of 700 mW, was used to initiate two-photon polymerisation. The axicon was used, in combination with a 100× microscope objective, to form representative three-dimensional structures based on the annular cell with varying diameter. The structures were written in a Zr-loaded resin prepared on a glass substrate using dip coating deposition of a Zr/PMMA hybrid prepared by the sol–gel method. Annuli with diameters up to 50 μm were characterised in terms of topography and surface roughness using SEM and Zygo interferometer. The writing technique was also extended to fabrication of stacked structures.

Two-photon polymerisation is an established technique for the fabrication of three-dimensional microstructures. To date structures have mostly been developed using single beam serial writing. A novel approach to simultaneous multi-spot two-photon polymerisation, that uses a SiO 2 on glass Fraunhofer diffractive optical element to generate an array of beamlets, is described. A Ti:sapphire laser, with wavelength 790 nm, 80 MHz repetition rate, 100 fs pulse duration and an average power of 25 mW, was used to initiate two-photon polymerisation. The DOE, in combination with a high power microscope objective, efficiently transforms the laser beam into a linear array of four spots of equal intensity. The fabrication of a periodic transmission grating, using parallel processing with these four spots, is shown. The grating was written in a Zr-loaded resin prepared on a glass substrate using dip coating deposition of a Zr/PMMA hybrid prepared by the sol–gel method. The operation of the diffractive element and the performance of the diffraction grating are also discussed.

Thin film systems consisting of (3-glycidyloxypropyl)trimethoxysilane (GDPTMS), dimethyldimethoxysilane (DMDMOS) and, either zirconium(IV) n -propoxide (Zr(OPr n ) 4 ) or diphenyldimethoxysilane (DPDMS) were synthesised via the sol–gel method. GDPTMS and DMDMOS were employed as the main network formers, whereas Zr(OPr n ) 4 or DPDMS was both a network former and a refractive index modifier. The comparative effects of Zr and DPDMS content, and UV light on the optical and thermal properties of the system were evaluated. Refractive index measurements and cross-sectional scanning electron microscopy of the resultant thin films were performed. The thermal stability of each system, in terms of temperature at 10% mass loss, was characterised by dynamic thermogravimetry. It was demonstrated that the selection of refractive index modifier along with UV irradiation plays an important role in tuning the optical and thermal properties of an epoxy-functional inorganic-organic hybrid sol–gel derived thin film system.

An inorganic–organic hybrid material system consisting of (3-glycidyloxypropyl)trimethoxysilane, dimethyldimethoxysilane and zirconium(IV) n-propoxide was prepared by the sol–gel method. The influence of processing parameters including Zr content, UV irradiation and sol ageing on the thermal stability of the resultant thin films was characterised by thermogravimetry. It was demonstrated that the crosslinking of epoxy groups in the structure was the primary reason for variation in the thermal stability of the system. As Zr and/or UV irradiation may be employed to crosslink the epoxy groups in the structure, the thermal stability of the system can be tuned by the optimal combination of these two crosslinking methods.

A hybrid material system consisting of (3-glycidyloxypropyl)trimethoxysilane and dimethyldimethoxysilane as matrix materials and diphenyldimethoxysilane (DPDMS) as both a matrix material and a potential thermal stabiliser by the sol–gel method. A detailed thermogravimetric analysis study of the influence of processing parameters, including DPDMS content, UV irradiation and sol ageing, on the thermal stability of the resultant thin films was presented. FT-IR spectroscopy was used to monitor the changes in the relative amount of epoxy rings in the system during processing. It was demonstrated that the crosslinking of epoxy groups in the structure is the primary reason for changes in the thermal stability of the system. It was also shown that the thermal stability, in terms of 10% mass loss, of the material system could be improved up to 280 °C, by adjusting the preparation conditions, compatible with several subsequent high temperature optoelectronic integration processes.

A hybrid material system consisting of (3-glycidyloxypropyl)trimethoxysilane, dimethyldimethoxysilane and zirconium(IV) n-propoxide was prepared. The influence of processing parameters including Zr content, UV irradiation and sol ageing on the properties of the resultant thin films was discussed. Refractive index, at 633 nm, and reflectance measurements were performed and near-field waveguide images of the samples were taken. Optical propagation loss measurements, at 633 nm, were studied. Film thickness and cross-sectional scanning electron microscopy images were obtained as a function of process conditions. FT-IR spectroscopy was used to monitor chemical reaction pathways in the system during processing. It was demonstrated that the crosslinking of epoxy groups in the structure, along with inorganic network formation as a result of sol-gel reactions, was the primary reason for the changes in the optical and physical properties of the system. As Zr containing species and/or UV irradiation may be employed to crosslink the epoxy groups in the structure, the optical and physical properties of the system can be tuned by optimal combination of these two crosslinking methods, as well as sol ageing process.

Two-photon polymerisation of photo-sensitive materials allows the fabrication of three dimensional micro- and nano-structures for photonic, electronic and micro-system applications. However the usable process window and the applicability of this fabrication technique is significantly determined by the properties of the photo-sensitive material employed. In this study investigation of a custom inorganic–organic hybrid system, cross-linked by a two-photon induced process, is described. The material was produced by sol–gel synthesis using a silicon alkoxide species that also possessed methacrylate functionality. Stabilized zirconium alkoxide precursors were added to the precursor solution in order to reduce drying times and impart enhanced mechanical stability to deposited films. This enabled dry films to be used in the polymerisation process. A structural, optical and mechanical analysis of the optimised sol–gel material is presented. A Ti:sapphire laser with 80 MHz repetition rate, 100 fs pulse duration and 795 nm is used. The influence of both material system and laser processing parameters including: laser power, photo-initiator concentration and zirconium loading, on achievable micro-structure and size is presented.

Ferroelectric strontium bismuth tantalate (SBT) thin films were deposited by thermal metalorganic chemical vapour deposition (MOCVD) onto a complex layered Pt/IrO 2 /Ir/Ti(Al)N substrate. A study of ultra-violet (UV)-assisted rapid thermal processing (RTP) annealing strategies of the SBT thin films was performed. The influence of UV irradiation temperature and annealing atmosphere on the crystallinity of the deposited films was evaluated using both microstructural and electrical analysis techniques. A UV-RTP strategy in an oxygen atmosphere above 400 °C, followed by a furnace treatment at 700 °C, provided an optimum remnant polarization figure of merit.

High-performance metal-insulator-metal (MIM) capacitors using novel Pb(Mg0.33Nb0.67)0.65Ti0.35O3 (PMNT) thin films were fabricated and investigated. The dielectric properties of the PMNT capacitors were characterized at both dc and radio frequencies. A significant high-κ of 1115 (high capacitance density of 26 fF/μm2) for a PMNT MIM capacitor has been achieved. In addition, small leakage current density of 2 × 10-10 A/cm2 and low loss tangent of 0.0188 are also obtained. The results indicate that high-κ PMNT is a promising candidate material for high-performance MIM capacitors.

Identification of putative drug candidates by high throughput screening is assuming enormous importance within the pharmaceutical industry, driven by increasing numbers of valid therapeutic targets...