Sensing the force digitally Our skin provides us with a flexible waterproof barrier, but it also contains sensor array that feels world around us. This feedback and helps to avoid hot object or increase strength of our grip on an may be slipping away. Tee et al. describe approach simulate mechanoreceptors human skin, using pressure-sensitive foils printed ring oscillators (see Perspective by Anikeeva Koppes). The successfully converted pressure into digital response in range comparable found...

Indium–gallium nitride (InGaN) multiple-quantum-well (MQW) light-emitting diode (LED) membranes, prefabricated on sapphire growth substrates, were created using pulsed-excimer laser processing. The thin-film InGaN MQW LED structures, grown first bonded onto a Si support substrate with an ethyl cyanoacrylate-based adhesive. A single 600 mJ/cm2, 38 ns KrF (248 nm) excimer pulse was directed through the transparent sapphire, followed by low-temperature heat treatment to remove substrate....

Indium–gallium nitride (InxGa1−xN) single-quantum-well (SQW) light emitting diodes (LEDs), grown by metalorganic chemical vapor deposition on sapphire, were transferred onto Si substrates. The thin-film InxGa1−xN SQW LED structures first bonded a n+-Si substrate using transient-liquid-phase Pd–In wafer-bonding process followed laser lift-off technique to remove the sapphire growth substrate. Individual, 250×250 μm2, LEDs with backside contact through then fabricated. had typical turn-on...

During short-pulse laser crystallization of amorphous silicon on quartz, surface roughening occurs via the freezing capillary waves excited in melt. The velocity and viscous damping these is computed discussed. Volume change during solidification appears to drive liquid toward last areas solidification. Film thickness variation observed by transmission electron microscopy atomic force shows increased film at grain boundaries, vertices single pulse irradiated films. This effect most...

The intermixing of AlAs-GaAs superlattices has been investigated as a function Si concentration following anneals in the range 500 to 900 °C. superlattice samples were grown by molecular beam epitaxy and near surface layers doped with silicon at concentrations 2×1017 5×1018 cm−3. Al depth profiles measured secondary ion mass spectrometry (SIMS). diffusion length activation energy dopant derived from SIMS data. In temperature studied single for ∼4 eV was observed, coefficients increased...

A low temperature process for laser dehydrogenation and crystallization of hydrogenated amorphous silicon (a-Si:H) has been developed. This removes hydrogen by irradiations at three energy steps. Studies out-diffusion microstructure show that depends strongly on film structure the density. Both high quality leakage bottom gate polycrystalline a-Si:H thin transistors were monolithically fabricated same Corning 7059 glass substrate with a maximum only 350 °C.

The effects of Si ion implantation and annealing on AlAs-GaAs superlattices are examined with secondary mass spectrometry (SIMS), Rutherford backscattering (RBS), transmission electron microscopy (TEM). Samples implanted 180 keV 28Si+ doses ranging from 3×1013 to 3×1015 cm−2 before after a 3-h 850 °C anneal. Both the TEM RBS channeling data indicate formation heavily damaged surface layer where diffusion Al is inhibited even thermal annealing. After annealing, however, significant mixing...

Recent studies have shown that Zn diffusion preferentially induces mixing (interdiffusion) of In and Ga in unstrained InGaAs/InP superlattices, with little the anions. present study, a 3.1% lattice mismatch is accommodated mixed superlattice no observable defects layers on order predicted critical layer thickness. At high concentrations, resides InP form Zn3P2. marked contrast to this behavior Zn, Si observed cause comparable interdiffusion cation anion sublattices within narrow range dopant...

Abstract— The manufacture of large‐area arrays thin‐film transistors on polymer substrates using roll‐to‐roll (R2R) processes exclusively is being developed. Self‐aligned imprint lithography (SAIL) enables the patterning and alignment submicron‐sized features meter‐scaled flexible in R2R environment. SAIL solves problem precision interlayer registry a moving web by encoding all geometry information required for entire steps into monolithic three‐dimensional with discrete thickness...

Abstract We have demonstrated a printed electronic tag that monitors time-integrated sensor signals and writes to nonvolatile memories for later readout. The is additively fabricated on flexible plastic foil comprises thermistor divider, complementary organic circuits two memory cells. With supply voltage below 30 V, the threshold temperatures can be tuned between 0 °C 80 °C. time-temperature dose measurement calibrated minute-scale integration. bits are sequentially written in thermometer...

We demonstrate the feasibility of polycrystalline nitride semiconductor light-emitting diodes (LEDs). Here, LEDs were deposited on quartz substrates, incorporating a layer structure identical to that used for epitaxially grown LEDs. The deposition exhibits tendency produce c-oriented crystallites. Violet-blue (430 nm) operation LED is demonstrated, with spectral width 38 nm, and emission efficiency approximately two orders magnitude lower than single-crystal These could potentially be...

Printed organic electronics are being explored for a wide range of possible applications, with much the current focus on smart labels, wearables, health monitoring, sensors and displays. These applications typically integrate various types often include silicon integrated circuits (IC) computation wireless communications. Organic thin film transistors (TFT), particularly when printed, have performance yield limitations that must be accommodated by circuit design. The design also needs to...

Continuous-wave (cw) indium-gallium nitride multiple-quantum-well laser diodes (LDs) were transferred from sapphire onto copper substrates using a two-step lift-off process. Reduced threshold currents and increased differential quantum efficiencies measured for LDs on Cu due to 50% reduction of the thermal impedance. Light output was three times greater than comparable with maximum 30 mW. CW operation possible up heatsink temperatures 90 °C Cu.

Selective dehydrogenation and crystallization are realized by a three-step incremental increase in laser energy density. X-ray diffraction transmission electron microscopy show that the polycrystalline grains formed with this process similar to those after conventional one-step of unhydrogenated amorphous silicon. The grain size increases increasing density up peak value few micrometers. decreases further transistor field effect mobility is correlated material properties, gradually until...

To enable the integration of components with different supply voltage requirements, and to optimize power consumption in printed flexible electronics, we demonstrate an inkjet-printed pulsed multiplier that boosts at specific circuit nodes above voltage. A five-stage is shown provide output up 18 V from a 10 V, minimum ms pulse rise time for 70 pF load. This allows single source deliver multiple levels enables low-voltage logic require higher operating key requirement low device leakage...

Two dimensional amorphous silicon arrays are the emerging technology for digital medical X-ray imaging. This paper demonstrates an improved pixel design compared with current generation of imagers. The geometry sensor has been extended from a mesa isolated structure into continuous layer above readout structures array. approach improves sensitivity to visible light, and illumination when coupled conversion phosphor. Furthermore, this 3-dimensional allows fabrication finest pitch array yet...

The species dependence of ion-induced superlattice mixing has been examined in AlAs-GaAs samples grown by molecular beam epitaxy. interdiffusion the superlattices induced ion implantation with comparable ranges, doses, and subsequent thermal anneals were measured secondary mass spectrometry. effects elements (Ga, As, Ge) valence (Si studied. experimental results show that Ga As cause primarily collision-induced mixing, while Ge additional impurity-induced beyond implant range. In comparison...

A solution to the problems of roll-to-roll lithography on flexible substrates is presented. We have developed a roll-toroll imprint technique fabricate active matrix transistor backplanes webs polyimide that blanket material stack metals, dielectrics, and semiconductors. Imprint produces multi-level 3- dimensional mask then successively etched pattern underlying layers into desired structures. This process, Self-Aligned Lithography (SAIL), solves layer-to-layer alignment problem because all...

A process design kit (PDK) or Technology Design (TDK) is a set of files which describes manufacturing parameters that are relevant for the designers (fabrication layers, electrical and rules) certain technology given foundry. PDKs customize CAD/EDA tools used by designers, providing enough abstraction technological details to facilitate (organic electronics) circuits. rules geometric restrictions imposed different layers fabricated foundry have respect. By taking into account, engineers...

The x-ray imaging performance is reported using polycrystalline lead iodide as a thick semiconductor detector on an active matrix flat panel array. We have developed test image sensor with 100 micron pixel size in 512 X format, amorphous silicon TFTs for addressing. new 14 bit electronic system allows radiographic and fluoroscopic imaging. PbI<SUB>2</SUB> has larger absorption higher charge generation efficiency than selenium, the potential sensitivity films are deposited by vacuum...

Pulsed excimer-laser processing of amorphous silicon on non-crystalline substrates is an important technology for large-area polysilicon electronics, such as flat-panel displays and two-dimensional imaging arrays. It also allows the integration devices same glass substrate provides procedures doping self-aligned thin-film transistors. Materials studies show that laser-crystallized exhibits a narrow peak in average grain size function excimer laser energy density, with corresponding electron...

The enhanced layer interdiffusion in Te-doped AlAs/GaAs superlattices has been studied by secondary ion mass spectrometry. superlattice sample was grown organometallic chemical vapor deposition with Te doping at concentrations of 2×1017–3×1018 cm−3 during the growth process. In temperature range from 800 to 1000 °C, Al diffusion coefficient an activation energy 3.0 eV and is approximately proportional concentration. These results contrast sharply Si-induced mixing which, analogous...

Inkjet printing on pre-fabricated high-resolution substrate is developed to improve the operational speed of printed organic transistors. The features are designed define transistor critical dimensions, while maintaining flexibility incorporate different circuit constructions. Logic gate and ring oscillator circuits fabricated by inkjet demonstrated, show that same high resolution pattern can be adapted for constructing electronic circuits.

We report on a-Si direct detection x-ray image sensors with polycrystalline PbI<SUB>2</SUB>, and more recently HgI<SUB>2</SUB>. The arrays have 100 micron pixel size and, we study those aspects of the detectors that mainly determine DQE, such as sensitivity, effective fill factor, dark current noise, noise power spectrum, absorption. Line spread function data show in PbI<SUB>2</SUB> arrays, most signal gap between pixels is collected, which important for high,DQE. leakage agrees expected...