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RFID tags are embedded in everyday objects providing extra functionalities and aiming to connect them to the cloud. Miniaturization of flexible RFID tags enables the integration into smaller everyday health, entertainment, food related objects, besides enhancing security and decreasing the cost. In addition, external sensor integration and readout enable new applications for the sensor tags. In this paper a miniaturized 2cm (1€ coin size) diameter antenna is combined with a flexible InGaZnO thin-film RFID chip operating at 3V and transmitting data at 7.3kHz. Moreover, the sharp threshold detection (

ispartof: pages:547-550 ispartof: SID's Digest of Technical Papers vol:51 issue:1 pages:547-550 ispartof: SID Display Week location:online status: Published online

With the advent of the internet of things, flexible wearable devices are gaining significant research interest, as they are unobtrusive, comfortable to wear and can support continuous observation of physiological signals, helping to monitor wellness or diagnose diseases. Amorphous Indium Gallium Zinc Oxide (a-IGZO) Thin Film Transistors (TFTs) fabricated on flexible substrates are an attractive option to build such bio-signal monitoring systems due to their flexibility, conformability to the human body, and low cost. This paper presents a flexible electrocardiogram (ECG) patch implemented on foil with self-aligned IGZO TFTs, which is capable to acquire the ECG signals, amplify them and convert them to a sequence of bits. The analogue frontend has a measured input-referred noise of 8 μVrmsin the 1–100 Hz band. The system achieves experimentally 67.4 dB CMRR, 58.9 dB PSRR, and 16.5 MΩ input impedance at 50 Hz while using 1 kHz chopping. The signal from the electrodes is transformed to a 105.9-kb/s Manchester-encoded serial bit stream which could be sent wirelessly to a smart phone via Near Field Communication (NFC) for further elaboration. Power consumption is 15.4 mW for the digital and 280 μW for the analogue part. This contribution shows the fundamental steps to demonstrate intelligent plasters for biomedical applications based on flexible electronics providing an NFC-compatible digital output bit stream.

Capacitive touchscreens are increasingly widespread, featuring in mobile phones and tablets, as well as everyday objects such as cars and home appliances. As a result, the interfaces are uniquely placed to provide a means of communication in the era of the Internet of Everything. Here we show that commercial touchscreens can be used as reader interfaces for capacitive coupled data transfer. The transfer of data to the touchscreen is achieved using a 12-bit thin-film capacitive radio frequency identification tag powered by a thin-film battery or a thin-film photovoltaic cell that converts light from the screen. The thin-film integrated circuit has a 0.8 cm2 on-chip monolithic antenna, employs 439 transistors, and dissipates only 31 nW of power at a supply voltage of 600 mV. The chip has an asynchronous data rate of up to 36 bps, which is limited by the touchscreen readout electronics. ispartof: NATURE ELECTRONICS vol:2 issue:12 pages:606-611 ispartof: location:England status: published

We present a qHD (960 × 540 with three sub-pixels) top-emitting active-matrix organic light-emitting diode display with a 340-ppi resolution using a self-aligned IGZO thin-film transistor backplane on polyimide foil with a humidity barrier. The back plane process flow is based on a seven-layer photolithography process with a CD = 4 μm. We implement a 2T1C pixel engine and use a commercial source driver IC made for low-temperature polycrystalline silicon. By using an IGZO thin-film transistor and leveraging the extremely low off current, we can switch off the power to the source and gate driver while maintaining the image unchanged for several minutes. We demonstrate that, depending on the image content, low-refresh operation yields reduction in power consumption of up to 50% compared with normal (continuous) operation. We show that with the further increase in resolution, the power saving through state retention will be even more significant.

Among the diverse and ever-expanding list of candidate technologies to serve the Internet of Everything, the rise of thin-film transistors on plastic as active components for ubiquitous ICs has been nothing short of meteoric. The stage for this explosion of interest was set by a pivotal advantage of the low manufacturing cost and ultrathin form factor, as demonstrated in recent prototypes of thin-film radio frequency identification (RFID) tags. Most RFID tags use inductive antennas, whereas, in this paper, capacitively coupled antenna is presented. Advantages of capacitive-coupled tags are the monolithic integrated antenna, the compact size, the additional security due to very short range of operation, and the localization and orientation abilities. The main circuit block of the tag, a 12-bit code generator, is demonstrated achieving only 160 nW of power dissipation at 0.3 V power supply transmitting data at 810 b/s on a 18 $\mu \text{m}$ -thick plastic substrate. The footprint of the monolithic integrated antenna is 1 cm2 and essentially defines the size of the full tag.

The antenna of the tag is monolithic integrated ”onchip”. The footprint of the tag is defined by the size of the antenna, 1cm2. The tag operated at 24V applied reader voltageat a frequency of 1MHz. The achieved data transmission speed of the thin-film tag is 5.8kbps. The technology is a unipolar indium gallium zinc oxide (IGZO) self-aligned transistor architectur.

In this paper a capacitive coupled radio-frequency identification tag fabricated on flexible thin-film substrate is presented. The antenna of the tag is monolithic integrated “on-chip”. The footprint of the tag is defined by the size of the antenna, 1cm2. The tag operated at 24V applied reader voltage at a frequency of 1MHz. The achieved data transmission speed of the thin-film tag is 5.8kbps. The technology is a unipolar indium gallium zinc oxide (IGZO) self-aligned transistor architecture.

In this study, we have compared the performance of self-aligned a-IGZO thin-film transistors (TFTs) whereby the source/drain (S/D) region's conductivity enhanced in three different ways, that is, using SiNx interlayer plasma (hydrogen diffusion), using calcium (Ca as reducing metal) and using argon plasma (changing the atomic ratio). All these TFTs show comparable characteristics such as field-effect mobility (μFE) of over 10.0 cm2/(V.s), sub-threshold slope (SS-1) of 0.5 V/decade, and current ratio (ION/IOFF) over 108. However, under negative-bias-illumination-stress (NBIS), all these TFTs showed strong degradation. We attributed this NBIS stability issue to the exposed S/D regions and changes in the conductivity of S/D contact regions. The hydrogen plasma-treated TFTs showed the worst NBIS characteristics. This is linked to increased hydrogen diffusion from the S/D contact regions to the channel. In this study, we observed that the negative-bias-illumination-stress stabilities of self-aligned a-IGZO thin-film transistors are strongly dependent upon the source/drain (S/D) region's direct exposure to stress light. Among few different techniques for S/D conductivity enhancements such as metal reduction (Ca metal), Ar plamsa, and SiNx plasma (hydrogen diffusion), the SiNx plasma-treated thin-film transistors showed the worst negative-bias-illumination-stress suitabilities. This is linked to increased hydrogen diffusion from the S/D contact regions to the channel. cop. 2015 Society for Information Display.

We present a QVGA (320x240 with 3 sub-pixel) top-emitting AMOLED display with 250ppi resolution using a self-aligned (SA) IGZO TFT backplane on polyimide-foil with full barrier. The back plane process flow is based on a 7 layer photolithography process. The aperture ratio of the top-emitting OLEDs is approx. 80%. An integrated gate driver is shown that can be driven at operation speed equivalent to a 4k2k display at 100Hz

In this work we present the impact of buffer layers deposited by various techniques such as plasma enhanced chemical deposition (PECVD), physical vapor deposition (PVD) and atomic layer deposition (ALD) techniques on self-aligned (SA) top gate amorphous-Indium-Gallium-Zinc-Oxide (a-IGZO) TFT characteristics. Finally an optimized layer was integrated in TFT backplane on polyimide (PI) foil and a QQVGA AMOLED display is demonstrated.

We demonstrated self-aligned amorphous-Indium-Gallium-Zinc-Oxide (a-IGZO) thin-film transistors (TFTs) where the source–drain (S/D) regions were made conductive via chemical reduction of the a-IGZO via metallic calcium (Ca). Due to the higher chemical reactivity of Ca, the process can be operated at lower temperatures. The Ca process has the additional benefit of the reaction byproduct calcium oxide being removable through a water rinse step, thus simplifying the device integration. The Ca-reduced a-IGZO showed a sheet resistance (RSHEET) value of 0.7 kΩ/sq., with molybdenum as the S/D metal. The corresponding a-IGZO TFTs exhibited good electrical properties, such as a field-effect mobility (μFE) of 12.0 cm2/(V s), a subthreshold slope (SS−1) of 0.4 V/decade, and an on/off current ratio (ION/OFF) above 108. Cop. 2015 The Korean Information Display Society.

We present a qHD (960x540 with 3 sub-pixels) top-emitting AMOLED display with 340ppi resolution using a self-aligned (SA) IGZO TFT backplane on polyimide-foil with humidity barrier. The back plane process flow is based on a 7 layer photolithography process with a CD=4um. We implement a 2T1C pixel engine and use commercial source driver IC made for LTPS. By using IGZO TFT and leveraging the extremely low off-current, we can switch-off the power to the source and gate driver while maintaining the image un-changed for several minutes. We demonstrate that, depending on the image content, low-refresh operation yields reduction in power consumption of up to 50% compared to normal (continuous) operation. We show that with further increase in resolution, the power saving through state retention will be even more significant.

A process to make self-aligned top-gate amorphous indium-gallium-zinc-oxide (a-IGZO) thin-film transistors (TFTs) on polyimide foil is presented. The source/drain (S/D) region's parasitic resistance reduced during the SiN interlayer deposition step. The sheet resistivity of S/D region after exposure to SiN interlayer deposition decreased to 1.5 kΩ/□. TFTs show field-effect mobility of 12.0 cm2/(V.s), sub-threshold slope of 0.5 V/decade, and current ratio (I ON/OFF) of >107. The threshold voltage shifts of the TFTs were 0.5 V in positive (+1.0 MV/cm) bias direction and 1.5 V in negative (-1.0 MV/cm) bias direction after extended stressing time of 104 s. We achieve a stage-delay of ~19.6 ns at V-DD = 20 V measured in a 41-stage ring oscillator. A top-emitting quarter-quarter-video-graphics-array active-matrix organic light-emitting diode display with 85 ppi (pixels per inch) resolution has been realized using only five lithographic mask steps. For operation at 6 V supply voltage (V-DD), the brightness of the display exceeds 150 cd/m2. A process to make self-aligned top-gate amorphous indium-gallium-zinc-oxide (a-IGZO) thin-film transistors (TFTs) is presented. TFTs show field-effect mobility of 12.0 cm2/(V.s), sub-threshold slope of 0.5 V/decade, and current ratio (I ON/OFF) of over 107. In applications, a 41-stage ring oscillator with a stage-delay of ~19.6 ns (at V-DD = 20 V) and a top-emitting quarter-quarter-video-graphics-array (QQVGA) active-matrix organic light-emitting diode (AMOLED) display with 85 ppi (pixels per inch) resolution using five lithographic mask steps have been realized on a polyimide foil. Copyright 2015 Society for Information Display.

We present a QQVGA (160times120 with 3 sub-pixel) top-emitting AMOLED display with 85ppi resolution using a self-aligned (SA) IGZO TFT backplane on polyimide-foil. The back plane process flow is based on a 5 layer photolithography process. The aperture ratio of the top-emitting OLEDs is approx. 25%. For operation at 6 V supply voltage (VDD), the brightness of the display exceeds 150cd/m2. On the same substrate a 160 stage gate-driver was measured at FHD rate. cop. 2014 Society for Information Display.

We show an active artificial iris based on solely thin-film components, wherein several LCD elements are controlled a metal-oxide TFT and by powered by thin-film photovoltaics (TFPV). Key aspects for the driver are size and low power consumption. We demonstrate power consumption down to 25μW for the full iris.

In this study, we report high-quality amorphous indiunrv-galiium-zinc-oxide (a-IGZO) thinfilm transistors (TFTs) fabricated on a polyethylene naphthalate foil using a new back-channel-etch (BCE) process flow. The BCE flow allows a better scalability of TFTs for high-resolution backplanes and related circuits. The maximum processing temperature was limited to less than loS'C in order to ensure good overiay accuracy (

In this study, the authors report high-quality amorphous Indium-Gallium-Zinc-Oxide (a-IGZO) thin film transistors (TFTs) fabricated using a new back-channel-etch (BCE) process flow on Polyethylene Naphthalate (PEN) foil. The BCE flow allows a better scalability of TFTs for high-resolution backplanes and related circuits. The maximum processing temperature was limited to less than 165oC in order to ensure good overlay accuracy (< 1µm) on foil. The presented process flow differs from to previously reported by defining the Mo S/D contacts by dry etch prior to a-IGZO patterning. The TFTs show good electrical performance, including field-effect mobilities in the range of 15.0cm2/(V.s), sub-threshold slopes of 0.3V/decade and off-currents

We have developed a full color flexible top-emission AMOLED display with 80 ppi resolution using In-Ga-Zn-O TFT backplane on PEN foil under the maximum process temperature of 150 oC. Notwithstanding the low processing temperature, the TFTs with SiOx passivation layer show high reliability with VTH shift of less than 0.2 V at 10,000 seconds under bias-stress of -10 V. cop. 2013 Society for Information Display.

AMOLED backplanes were fabricated on both rigid glass and flexible plastic substrates using a solution processed oxide semiconductor processed at temperatures

A target application for plastic RFID tags is Electronic Product Coding (EPC). The EPC-specifications set some demanding requirements for RFID tags. In this work, we review the work that has been done to fulfill some of these specifications. We describe a complete 64-bit RFID tag that is inductively-coupled at a base carrier frequency of 13.56 MHz, and transmits data at rates below 1 kb/s. Next, we demonstrate 8-bit RFID transponder chips having data rates of 50 kb/s, an important milestone for organic RFID tags in view of EPC specifications.

The Internet of Things is driving extensive efforts to develop intelligent everyday objects. This requires seamless integration of relatively simple electronics, for example through `stick-on' electronics labels. We believe the future evolution of this technology will be governed by Wright's Law, which was first proposed in 1936 and states that the cost of a product decreases with cumulative production. This implies that a generic electronic device that can be tailored for application-specific requirements during downstream integration would be a cornerstone in the development of the Internet of Things. We present an 8-bit thin-film microprocessor with a write-once, read-many (WORM) instruction generator that can be programmed after manufacture via inkjet printing. The processor combines organic p-type and soluble oxide n-type thin-film transistors in a new flavor of the familiar complementary transistor technology with the potential to be manufactured on a very thin polyimide film, enabling low-cost flexible electronics. It operates at 6.5 V and reaches clock frequencies up to 2.1 kHz. An instruction set of 16 code lines, each line providing a 9 bit instruction, is defined by means of inkjet printing of conductive silver inks. ispartof: Scientific Reports vol:4 issue:1 ispartof: location:England status: published

We present experimental results using an alternative cross-linker for poly(4-vinylphenol) (PVP) that allows lowering of the thermal budget of the cross-linking reaction to 130 °C which compares very favorable to the 180 °C required by the commonly used cross-linking agent poly(melamine-co- formaldehyde). Furthermore, we characterize the dielectric properties of a 200 nm thick layer and realize high quality organic thin film transistors using this low-temperature PVP as a gate-dielectric. © 2010 Elsevier B.V. All rights reserved. ispartof: Thin Solid Films vol:519 issue:1 pages:391-393 status: published

Organic RFID tags are increasingly gaining credibility as a possible low-cost barcode replacement for product identification. This will only happen if organic RFID tags can operate in the frequency range defined by well-accepted EPC standards. This chapter evaluates the performance of existing organic RFID demonstrators and confirms that, based on lab scale demonstration of organic RFID tags, performance comparable to the EPC standards can be obtained. Moreover, the integration of sensors with the tags will enable added functionality and applications beyond pure identification.

We present a QQVGA top emitting monochrome AMOLED display with 85dpi resolution using an organic TFT backplane on low temperature PEN-foil. The backplane process flow is based on a 7 layer photolithography process that yields a final mobility of the OTFT of ∼0.4 cm2/Vs. The aperture ratio of the top-emitting OLEDs is over 75%. For operation at 10 V supply voltage (VDD), the brightness of the display using red and green OLEDs exceeds 200 cd/m2.

Short channel organic thin film transistors in bottom-gate, bottom contact configuration use typically gold metallization for the source and drain contacts because this metal can easily be cleaned from photoresist residuals by oxygen plasma or ultraviolet-ozone and allows also surface modification by self-assembled monolayers (e.g. thiols). Alternative low-cost bottom contact metallization for high performance short-channel organic thin film transistors are scarce because of the incompatibility of the bottom contact material with the cleaning step. In this work a new process flow, involving a temporary thin aluminum protection layer, is presented. Short channel (3.4 μm) pentacene transistors with lithographical defined and thiol modified silver source/drain bottom contacts (25 nm thick, on a 2 nm titanium adhesion layer) prepared according to this process achieved a saturation mobility of 0.316 cm2/(V.s), and this at a metal cost below 1% of the standard 30 nm thick gold metallization.

In this chapter, fully integrated organic RFID tags are demonstrated. These tags are inductively-coupled at a base frequency of 13.56 MHz and can be read out at distances up to 10 cm, which is the expected readout distance for proximity readers. We also demonstrate next generation transponder chips, fabricated in a dual-gate technology. The additional gate, backgate, is used to control the threshold voltage and allows integration into more robust unipolar, dual-VT transponder chips. Finally, we realized an 8-bit transponder chip having data rates that are EPC-compatible. This has been achieved in our thin-film transistor technology by introducing a high-k Al2O 3 gate dielectric, by scaling the channel lengths down to 2 mm and by reducing the overlap capacitance of the parasitic source-gate and drain-gate capacitors. © 2011 Springer Science+Business Media B.V.

Pure gold layers are traditionally used for the fabrication of source/drain bottom contacts of high performance short channel pentacene transistors. In this work, these layers are successfully replaced by low cost metallic bilayers, consisting of a thick aluminum layer with a good electrical conductivity covered by a thin noble metal layer (gold or palladium) providing good charge injection into the organic semiconductor. Corresponding pentacene transistors with 5 μm channel length achieve saturation mobilities in the range of 0.4–0.5 cm 2 /(V s), comparable to those of reference pentacene transistors based on 30 nm thick pure gold bottom contacts, but for a metal cost down to 5% of that of the reference transistors.

In this work we present the instabilities observed in organic Thin-Film Transistors when subjected to stress test in different bias, temperature and illumination conditions. C-V measurements, indicate the presence of two distinct trapping phenomena. Appreciable charge trapping can be achieved using relatively high biases for long times (1000s). Illumination strongly enhances charge trapping only under positive gate biases, while it has no effect on the charge trapping/detrapping under negative gate bias. Charge detrapping is thermally activated coherently with trapping/detrapping at the SiO2/pentacene interface from hydrogenoid species. A first order model explaining the observed relaxation kinetics is also presented. ispartof: pages:334-341 ispartof: 2010 international reliability physics symposium pages:334-341 ispartof: 48TH Annual IEEE International Reliability Physics Symposium (IRPS) Anaheim, CA, MAY 02-06, 2010 location:CA, Anaheim date:2 May - 6 May 2010 status: published

Last year, advances in organic device technology (such as device scaling, high K-dielectrics [1], ... ) enabled a substantial progress in performance. This resulted in an increase in the data rate of plastic transponder circuits from about 2 kbit/s [21 to EPC-compatible speeds (SO kbit/s). The organic semiconductor pentacene deposited from solution was replaced by a better-performing vapor-phase deposited pentacene, with a mobility being a factor of 3 higher. The isolation of pentacene transistors in this new process is achieved by an integrated shadow mask, shown in Fig. 1, that results in a reliable isolation of the semiconductor area testified by off-currents below 10pA. We replaced the organic polymer (low-k) dielectric with a 100-nm thick high-k dielectric, sputtered AIz03, resulting in an 8-fold higher specific accumulation capacitance. That, in turn, allowed for downscaling the transistor channel length from 51lm to 211m, while maintaining a high output resistance in saturation - and therefore also high inverter gain and noise margins. A cross-section of this process flow is depicted in Fig. 1. Fig. 2 shows a micrograph image of a 5-stage ring oscillator realized in this technology on foil optimized for speed. This organic thin-film circuit technology allows to design with lower overlap capacitance and to downscale the transistor channel length, within the boundaries achievable by existing high-throughput manufacturing tools (e.g. steppers used in backplane manufacturing). In this work, we varied the channel lengths (L) of the TFTs in the circuits between 20μm and 2μm and limited the gate-source and gate-drain overlap capacitances by decreasing the width of the finger-shaped source and drain contacts, that fully overlap the gate, from 5μm to 2μm. Fig. 2 shows a micrograph image of one transistor. Typical transfer curves of transistors fabricated in this technology, having L = 5μm and 2μm, are depicted in Fig. 3 and Fig. 4 respectively. The transistors are normally-on and their charge carrier (hole) mobility exceeds 0.5cm2/Vs. Fig. 5 shows typical transfer curves of a zerovgs-load inverters with channel lengths of 5μm and 2μm. The ratio between drive and load transistor is 10:1. The inverters have high gains and noise margins. The stage delay (τD ) of inverters in this technology is plotted as a function of the supply voltage in Fig. 6. The stage delay is determined from 19-stage ring oscillators. The figure shows τD for inverters with channel lengths from 20μm to 2μm and gate-overlap of the transistor-fingers ranging from 5μm to 2μm. Stage delays below 1μS, and as low as 400ns, are shown at VDD=10V. To our knowledge, no plastic technology was shown before with such speeds at these low power voltages. The effect of decreasing the overlap capacitance is also shown for the two smaller channel lengths: shrinking the overlap from 5μm to 2μm improves the stage delay by a factor of 1.5 to 2. We proceeded with the design and realization of 8bit organic RFID transponder chips, having a channel length of 2μm and either 5μm or 2μm finger widths. Figs. 7 and 8 show the photographs of the 6″ wafer and a zoom of the die, Fig. 9 shows the corresponding schematic. Fig. 11 depicts the output signal of both types of transponders. In agreement with the two-fold faster inverter stage delay for the 2μm fingers, the data rate of this transponder is also twice as high as that of the design with 5μm fingers. The obtained data rate of the 8bit transponder with channel length and fingers of 2μm is a record 50kb/s. © 2010 IEEE.

In this paper a fully integrated organic DC-DC upconverter is presented in a pentacene p-type only technology. This 3-stage Dickson converter reaches a voltage conversion factor of 3 for a purely capacitive load and 2.5 for a 10 μA load current. The maximal output voltage goes up to 75 V and the Dickson core efficiency is 48 %. The clock signal is generated on-chip with a 9-stage ring oscillator, built with zero-Vgs load inverters. A tunable input voltage provides a tuning range of 30 %. The presented converter is designed for the on-chip generation of voltages for biasing a capacitive load. This converter draws 560 μA from a 20 V supply voltage. The chip area measures 2.8x2.1 mm2. This converter fulfills a direct need for bias voltages beyond the supply voltage that is uncovered in recent work on organic circuits. ©2010 IEEE.

We present our recent achievements in organic semiconductor technology in two emerging application areas. We show that the performance of our technology approaches the requirements for Electronic Product Coding RFID tags. Also, backplanes of OLED displays are enabled by the unique compatibility of pentacene transistors with high-k gate dielectrics. © 2009 IEEE.

Clusters of silver atoms and ions have attracted the interest of scientists because of their pronounced catalytic and emissive properties. To prevent aggregation of the clusters into larger particles, stabilization in gas matrices at cryogenic temperatures, or in scaffolds such as polyphosphates, DNA, peptides or polymers at ambient temperature, has been suggested. Alternatively, zeolites have been proposed to stabilize small ionic silver clusters. The molecular dimensions of the zeolite cages and channels prevent aggregation into larger nanoparticles (because of steric reasons) while the net negative charge of the zeolite lattice, the coordinating properties of the lattice oxygen atoms, and the presence of additional cations play a crucial role in stabilizing cationic clusters and unstable intermediates during reduction. Reduction of silver in zeolites is usually a bulk process that requires reductants, such as hydrogen gas or sodium borohydride, but also g irradiation and visible light can cause reduction. One of the most studied systems is silver-exchanged zeolite A (LTA topology), and several models have been proposed to explain the nature and location of the silver clusters formed in this zeolite upon reduction. Aside from their catalytic properties, oligonuclear silver clusters show particularly bright and stable luminescent properties. However, the existing fluorescence studies about Ag clusters in zeolites are limited to the excitation and emission spectra of bulk powder samples. Here, we report on bright fluorescent (spots in) individual silverexchanged zeolite 3A crystals obtained upon photoactivation using a focused UV irradiation on a fluorescence microscope. Photoactivation of silver has been demonstrated for nanoscale Ag2O particles (and interpreted as a photoreduction process). In our study, the emissive silver material is confined within a zeolite framework, which results in a better control of the type and location of the emissive species formed upon UV irradiation. Silver-cluster-loaded crystals are technologically very attractive—for example, as secondary light sources in fluorescence lamps—because of their high emission intensity, their excellent photostability upon UV irradiation, and their large Stokes shift. Moreover, the space-resolved selective activation of the emission intensity may have important applications in data storage. The emissive zeolite particles used herein were prepared by exchanging zeolite 3Awith (8 1)wt%Ag (fromAgNO3 solutions), followed by heating for one day at 450 8C (see the Supporting Information). The enhanced emission exhibited by the silver-exchanged zeolites after the thermal treatment has been ascribed to two possible causes: 1) to the formation of charge-transfer complexes between the partially (de)hydrated silver ions and the oxygen atoms in the zeolite lattice or 2) to the emissive properties of autoreduced oligoatomic silver clusters that may be formed during the high-temperature treatment. Although this report focuses on the photoactivation of thermally treated Ag zeolites, control experiments performed on not thermally activated Ag zeolites (dried at 110 8C) show an analogous photoactivation behavior (see the supporting Information). Figure 1a(1),b(1) shows typical confocal scanning images of a heat-treated Ag-containing zeolite crystal (roughly 3 ? 3 mm in size) taken under a confocal microscope using a picosecond-pulsed 375 nm excitation source (doubled Ti:Sapphire, Spectra Physics; see the Supporting Information). Figure 1a and 1b were taken at excitation intensities of 10 and 20 Wcm , respectively. Zeolite crystals that were not treated thermally exhibited an emission ten-times-weaker than that of the thermally treated samples. The confocal approach in combination with the pinhole in the emission path (see the Supporting Information) allows the collection of photoemission data from selected parts inside the crystals. Diffraction-limited bright spots can be generated at specific domains inside an individual crystal by simply focusing a low-power UV laser at the target position; for instance, in the crystal shown in Figure 1a, three individual spots were selectively activated by irradiation during [*] Dr. Y. Antoku, Dr. M. Sliwa, S. Smout, Prof. Dr. J. Hofkens, Dr. T. Vosch Department of Chemistry Katholieke Universiteit Leuven Celestijnenlaan 200F, 3001 Heverlee (Belgium) Fax: (+32)1632-7989 E-mail: tom.vosch@chem.kuleuven.be

We have prepared two fluorescent dyes derived from 8-(4-tolyl)-4,4-difluoro-4-bora-3a,4a-diaza-s-indacene with phenoxy and (o-bromo)phenoxy substituents at the 3,5-positions by a novel nucleophilic substitution reaction of the corresponding 3,5-dichloroBODIPY analogue. UV-vis absorption, steady-state and time-resolved fluorimetry have been used to investigate their solvent-dependent photophysical properties. The two BODIPY derivatives show narrow absorption and emission bands and display small Stokes shifts. The substituents at the 3,5-positions (phenoxy in 1 and o-bromophenoxy in 2) have a minor effect on the fluorescence quantum yields (0.16-0.40 for 1, 0.17-0.44 for 2) and lifetimes (1.09-2.51 ns for 1, 1.11-2.78 ns for 2). For both compounds, the fluorescence rate constant equals (1.5 +/- 0.1) x 10(8) s(-1).

In this work, we present the impact of S/D contact formation, that is, by SiN plasma doping (hydrogen incorporation), metallic reduction (by calcium) and by argon plasma (compositional change) on NBIS instabilities of self-aligned a-IGZO TFTs.

We have used nanoimprint lithography to fabricate organic in-plane diodes whose design and process are suitable for mass produced by roll to roll production for simple radio frequency circuitry. The diode characteristics are a result of a channel constriction with rectifying ratios up to 3.25 × 104. Above the threshold voltage their behavior is quadratic, and there is a non-quadratic relationship between the threshold voltage and channel width and channel length. The phenomenon is the resultant interaction of the distribution of the localized states and the additional in-plane transverse electric field through the device channel.