In this work, we report on development of one-dimensional reaction-diffusion simulator needed to understand the kinetics of Cu-related metastabilities observed in CdTe PV devices. Evolution of intrinsic and Cu-related defects in CdTe solar cells has been studied in time-space domain self-consistently with free carrier transport. Resulting device performance was simulated as a function of stress time, thus showing pronounced effect that the evolution of associated acceptor and donor states can cause on device characteristics. Although 1D simulation has intrinsic limitations when applied to poly-crystalline films, the results presented confirm the validity and the potential of the approach presented in better understanding of the performance and metastabilities of CdTe photovoltaic devices.

The goal of this research is to synthesize novel linear and hyperbranched polythiophene derivatives containing diketopyrrolopyrrole (DPP) as linking groups, and to investigate thermal, optical, electrochemical, and photovoltaic properties of those derivatives. Polymers with high regioregularity were synthesized via the Universal Grignard metathesis polymerization. Those linear or hyperbranched polythiophenes containing DPP bridging moieties showed higher molecular weights and better thermal stability compared with normal P3HT. The UV-vis absorption spectra of the DPP-containing polymers are similar to that of P3HT in film state, while they show distinct attenuation in fluorescent emission. Finally, all polymers were blended with PC61BM and used as active layers for fabrication of inverted solar devices. The devices based on those DPP-containing polythiophenes revealed the open-circuit voltage (V OC) of 0.55–0.58 V, the short-circuit current (J SC) of 8.62–16.21 mA/cm2, the fill factor (FF) of 36–41%, and the power conversion efficiency (PCE) of 1.73–3.74%.

In situ temperature-resolved Near-edge X-ray Absorption Fine Structure (NEXAFS) measurements were performed on thermo-active ethylene-vinyl acetate (EVA) – multiwall carbon nanotube (MWCNT) composites 12 months following synthesis, and compared with spectra acquired shortly after synthesis to examine aging effects on non-covalent interactions. Room temperature spectra revealed no difference between unstrained and strained composites, suggesting relaxation. Further, energy shifts in π* C=C resonances indicated a change in π–π interactions between MWCNT walls and chemical dispersant, supported also by AFM phase imaging. Temperature-resolved NEXAFS analysis showed a lack of interaction between nanotubes and polymeric chains, suggesting the chemical dispersant unlatched from MWCNT walls. The extent of this effect is finally quantified through a comparative study of spectral trends.

Inkjet printing of various nanoparticle inks, made from silver or copper nanoparticles, and its transformation into solid functional patterns is of high interest in the field of printed electronics. Liquid materials can be deposited as defined patterns in selected areas with micrometer precision. To convert these printed liquid films, consisting of solvents, additives and nanoparticles, into solid functional patterns a post-treatment is required. To this date, many investigations report on various sintering techniques to achieve e.g. high conductivity from the printed conductive materials.

Direct thermal sintering (via furnace or hotplate) requires high temperatures, which makes it not suitable for sensitive polymeric substrates. The novel method of intense pulsed light (IPL) sintering opens the window of opportunity to convert liquid or dried metal layers into solid functional layers within milliseconds without damaging the thermally fragile polymeric substrate.

In this work we present and analyze the application of the IPL sintering on inkjet printed silver patterns on various flexible substrates, like Poly(ethylene naphthalate) (PEN), Poly(ethylene terephthalate) (PET), Polyimide (PI) foils and paper.

A high dependency of the electrical and structural performance of the printed silver layers on the base substrate was observed when flashing with the IPL technique. Flashing parameters were varied and the resulting sheet resistance is presented.

With the analytical comparison of optical and electrical results, the flashing settings could be adapted to achieve highly conductive inkjet printed silver patterns on flexible substrates, when compared to other thermal sintering techniques. Furthermore the first integration of this post treatment methodology into semi-industrial roll-2-roll processing was successfully performed and will be demonstrated.

The effects of thermal treatments on the thermoluminescent (TL) signal of NaCl (ACS reagent) induced by gamma radiation were investigated. Samples of NaCl were thermally treated at 500, 800 and 1000 °C and characterized by X-Ray diffraction and scanning electron microscopy. After their exposure 0.1 to 150 Gy of gamma radiation from a gamma-ray source of 60Co, a TL curve for each temperature of treatment was obtained. We observed a different TL behavior on the irradiated samples as a function of the temperature applied during the thermal treatments. For the sample treated at 500 °C, three peaks centered at 102, 133 and 228 °C were observed. Samples treated at 800 and 1000 °C showed two main peaks at 128 and 220 °C and 136 and 219 °C, respectively; however, the highest TL intensity signal was observed for the sample at 800 °C. All samples showed a linear dependency of the integrated TL intensity from the signal emitted as function of the irradiation time. This is an important advantage because NaCl could be applied as a very low cost thermoluminescent dosimetric material. A comparison between the TL signal induced by gamma radiation in pure and Eu doped NaCl is also reported.

This work investigates the quality of back-channel passivation applied to sputter-deposited IGZO bottom-gate TFTs. Passivation materials investigated were alumina, silicon dioxide, and B-staged bisbenzocyclobutene-based (BCB) resins. Sputtered quartz and PECVD (TEOS) SiO2 rendered the IGZO material highly conductive (ρ < 0.01 Ω·cm), with subsequent annealing in oxidizing ambient unable to restore a high-resistivity state. Appropriate channel resistivity was restored on devices passivated with electron-beam evaporated alumina and spin-coated BCB when followed by annealing in air. Alumina passivated devices demonstrated improved stability; however slight distortions in measured I-V and C-V characteristics were observed. TCAD simulation was used to develop an IGZO material/device model, with results indicating the significant presence of oxygen-vacancy (OV) interface traps and negative fixed charge remaining at the back-channel.

This work presents an adsorption model based on the Sips isotherm for sensing different concentrations of DNA with open gate AlGaN/GaN high electron mobility field effect transistors (HEMTs). Probe-DNA was immobilized on the transistor gate before the application of target-DNA. Concentrations of 10-15 to 10-6 mol/L were tested. The sensor has a detection limit of 10-12 mol/L and saturates after the addition of 10-8 mol/L target-DNA.

The emission of crystalline silicon nanoparticles as well as nanowires can be tuned by varying their diameters. The diameter selection is achieved via a difficult chemical procedure that necessitates filtration which cannot be easily scaled up. Herein, we report a novel approach for producing and tuning the emission of freestanding colloidal of amorphous porous silicon nanoparticles (which should not be confused with bulk amorphous silicon nor with porous silicon) via a controlled oxidation without relying on size of nanoparticles. This oxidation increases local strain in the disordered network that causes orbital interactions which modifies the band-gap but a new hybridization.

We propose a theoretical designed peptide-Au cluster probe and realize spatially marking and quantitatively counting αIIbβ3 integrin via this novel nanoprobe. On single cell level, we find the number of αIIbβ3 integrin ranges from 5.75 to 9.11×10-17 mol for the heteroexpression of individual cells. Because the variation of proteins (including integrin and other biomarkers) on single cell has a tight correlation with many serious human diseases, our quantifying protein method on a single cell level is helpful for estimating the disease progression for diagnosis and detecting the drug response for therapy.

Desorption of gold ions from liver tissue sections, in which intravenously injected gold nanorods were accumulated, were studied to evaluate properties of gold nanorods as a "mass-tag". Gold ions were sensitively detected by using a conventional MALDI-MS machine. When 50-µm-thick blank sections without gold nanorods were placed on or beneath a sample section, desorption of gold ions was almost suppressed. It was found that the escape depth of gold ions from liver tissue sections was less than 50 µm. It was found that we do not have to take account of the escape depth of gold ions if a section were sliced into 10-20 µm thickness.

Results from the successful growth of high quality KH2PO4 (KDP) crystals with incorporated TiO2 anatase nanoparticles and the characterization of these crystals using several complementary methods are presented. Transmission and scanning electron microscopy have shown that the anatase nanoparticles were captured mainly by the pyramidal growth sector and, to a considerably lesser extent, by the prismatic growth sector. Energy dispersive x-ray analysis confirms that the growth layer stacks contain the TiO2 particles. Significant variation in the imaginary and real parts of the cubic nonlinear optical susceptibilities and refractive index changes at continuous wave excitation were found in prism and pyramid parts of pure KDP and KDP:TiO2 samples. The identified lines of electron paramagnetic resonance belong to four different centers FeA 3+, FeB 3+, CrR 3+ and CrGB 3+. From analysis of line intensities it was concluded that the concentration of non-controlled impurities in nominally pure KDP samples is several times larger than in KDP:TiO2, and that the concentration of non-controlled impurities in the prismatic part of the KDP:TiO2 boule is larger than in the pyramidal part.

In current transparent Si based photovoltaic (PV) module fabrication, green or infrared laser is the most common used band frequency to wipe off the silicon and back contact layer in perpendicular direction of cells. However, this method would result in more power loss than calculation value due to the side effects during the process such as constructional damage of module and shunt effect. A new method is presented here which focus on wiping off more silicon layer by employing green pulsed laser(532 nm wavelength) along the parallel direction of Pattern2, and it shows higher efficiency and more attractive appearance.

The growth of thin films of chemical vapour deposition (CVD) diamond onto flat samples of pure Zr has been studied using various CVD growth conditions in a hot filament reactor. We find that although growth is straightforward, adhesion of the diamond layer onto the Zr is poor, with the diamond layer often delaminating upon cooling. SIMS depth profiles show this to be due to the presence of a strongly-bonded native oxide on the Zr surface which is not removed in the reducing H2 atmosphere during CVD. This, plus the lack of any substantial carbide interfacial layer to ‘glue’ the diamond onto the surface, together with a poor thermal expansion mismatch between Zr and diamond, and the Zr hcp-to-bcc phase transition at ∼860°C, all lead to poor adhesion. Some of these difficulties can be reduced by depositing at lower temperature (<500°C) at the cost of poorer quality diamond.

An electrochemical impedance spectroscopy (EIS) corrosion study of API X70 steel was carried out in synthetic seawater with different rotation speeds using a rotating cylinder electrode (RCE) to control the hydrodynamic conditions at room temperature, atmospheric pressure and 24 h of exposure time. A superficial analysis through a scanning electron microscope (SEM) was used to analyze the corrosion type. The rotation speed used was 0 rpm (static condition), 1000, 3000 and 5000 rpm (turbulent flow). The results show that the turbulent flow conditions affect directly the corrosion rate (CR) of the steel, because all values of the CR under turbulent flow conditions are higher than the CR values at static conditions. In addition, it is important to point out that at turbulent flow conditions, the CR increased as the rotation speed also increased. The morphology of the corrosion in all experiments was localized corrosion.

Perovskite solar cells have caught wide attention. High efficiency, low-cost and high stability are among the major goals, which could eventually move the perovskite solar cells to the market. To achieve these goals, interface deliberation and nanostructural engineering hold the key.

Deformation behavior of MoSi2 has been studied by micropillar compressions of single crystalline specimens prepared by focused ion beam (FIB) technique as a function of crystal orientation at room temperature. Activation of the {011}<100> and {01 $\overline 3$ }<331> slip systems were observed in the micropillars compressed along [ $\overline 1$ 10] and [0 15 1], respectively. The CRSS values for each slip system exhibit an approximate power law relationship with the edge length of micropillar. The {01 $\overline 3$ }<331> slip exhibit much stronger size-dependence than the {011}<100> slip system.

We recently fabricated and characterized a new class of multilayer dielectric elastomer films comprising alternating layers of two different polymers, at least one of which is an elastomer. The films discussed here contain THV (a terpolymer of poly(vinylidene fluoride)) and poly(ethylene octene) [EO] elastomer. The multilayer structure provides improved dielectric and electromechanical performance relative to monolithic films of THV or EO. These properties are controlled by the composition and the layer structure. For example, increasing the concentration of the elastomeric EO component increases the maximum axial strain (sz). Layering EO with THV also increases the breakdown strength (E B ∼ 265 - 300 V/µm) relative to monolithic EO (E B ∼ 150 V/µm) or THV (E B ∼ 245 V/µm) control films. This enhancement in breakdown strength is consistent with a barrier effect that is also observed in multilayer polymer capacitor films. The increase in breakdown strength allows 512-layer 75 vol% EO / 25 vol% THV films to achieve maximum axial strains of s z nearly 4%, higher than can be attained by either EO or THV films alone. In addition, layering reduces remnant strain and electromechanical hysteresis by limiting the effective field within the THV layers. The 75% EO/ 25% THV films show robust operational longevity with little loss in axial strain when subjected to repeated actuation at E max = 225 V/µm (producing s z = 2.2%). Under these conditions, we observe 3,000 consecutive actuation cycles with no electrical breakdown. In comparison, single component EO control films undergo electrical breakdown at this field and THV control films survive only a few hundred actuation cycles under these conditions. The results demonstrate that multilayering is an effective technique to increase the dielectric strength of elastomer materials and in turn improve upon strain and operational longevity (repeated actuation cycles) characteristics.

Photovoltaic (PV) systems are progressively used for decentralized electricity generation. To obtain the maximum yield from such systems, optimisation of all components is essential. In this contribution, we provide a comprehensive modelling and sizing of PV systems for any location. Three applications are here presented providing real time monitoring of PV potential, accurate prediction of yield taking into account thermodynamic temperature effects, optimization of modules orientation addressing the effects of shading and efficient sizing of inverter for a higher yield output. When combined, these models can accurately predict the real time performance of any PV system.

The thermal conductivities of pillared-graphene nanostructures (PGNSs) are obtained using nonequilibrium molecular-dynamics simulation. It is revealed their thermal conductivities are much smaller than the thermal conductivities of carbon nanotubes (CNTs). This fact is explained by examining the density of states (DOS) of the local phonons of PGNSs. It is also found the thermal conductivity of a PGNS linearly decreases with the increase of the inter-pillar distance.