Gaining confidence in models of experiments in existing buildings

Describes a method for gaining confidence in models of experiments in existing buildings

Photo-Cross-Linkable Organic-Inorganic Hybrid Gate Dielectric for High Performance Organic Thin Film Transistors

In this study, we have demonstrated a novel organic-inorganic hybrid gate dielectric material, zirconium tetraacrylate (ZrTA). ZrTA gate dielectric, where inorganic Zr elements are embedded in organic acrylate matrix, takes advantage of the complementary properties of single organic or inorganic gate dielectrics. A simple spin-coating and UV-assisted cross-linking reaction of acrylate moieties allowed ZrTA film to be photopatterned The cross-linked ZrTA film by UV and heat treatments (UV, 365 nm for 3 min; heat, 120 degrees C for 30 min) showed high dielectric strength (10(-7) A/cm(2) at 2 MV/cm), and dielectric constant (5.48). In addition, surface properties of the ZrTA film (surface energy, surface roughness) were favorable for the growth of overlying pentacene organic semiconductor. Consequently, the organic thin-film transistor composed of a pentacene semiconductor and a cross-linked ZrTA gate dielectric displayed a moderately high field-effect mobility of 0.50 cm(2)/(V.s) with a negligible hysteresis transfer characteristic.1114Nsciescopu

Effects of Different Types of 3D Rest Frames on Reducing Cybersickness in a Virtual Environment

A virtual environment (VE) presents several kinds of sensory stimuli for creating a virtual reality. Some sensory stimuli presented in the VE have been reported to provoke cybersickness, which is caused by conflicts between sensory stimuli, especially conflicts between visual and vestibular sensations. Application of a rest frame has been known to be effective on reducing cybersickness by alleviating sensory conflict. The form and the way rest frames are presented in 3D VEs have different effects on reducing cybersickness. In this study, two different types of 3D rest frames were created. For verifying the rest frames' effects in reducing cybersickness, twenty subjects were exposed to two different rest frame conditions and a non-rest frame condition after an interval of three days in 3D VE. We observed the characteristic changes in the physiology of cybersickness in terms of autonomic regulation. Psychophysiological signals including EEG, EGG, and HRV were recorded and a simulator sickness questionnaire (SSQ) was used for measuring the intensity of the sickness before and after the exposure to the different conditions. In the results, the SSQ was reduced significantly in the rest frame conditions. Psychophysiological responses changed significantly in the rest frame conditions compared to the non-rest frame condition. The results suggest that the rest frame conditions have condition-specific effects on reducing cybersickness by differentially alleviating aspects of visual and vestibular sensory conflicts in 3D VE

Direct growth of graphene-dielectric bi-layer structure on device substrates from Si-based polymer

To facilitate the utilization of graphene films in conventional semiconducting devices (e.g. transistors and memories) which includes an insulating layer such as gate dielectric, facile synthesis of bi-layers composed of a graphene film and an insulating layer by one-step thermal conversion will be very important. We demonstrate a simple, inexpensive, scalable and patternable process to synthesize graphene-dielectric bi-layer films from solution-processed polydimethylsiloxane (PDMS) under a Ni capping layer. This method fabricates graphene-dielectric bi-layer structure simultaneously directly on substrate by thermal conversion of PDMS without using additional graphene transfer and patterning process or formation of an expensive dielectric layer, which makes the device fabrication process much easier. The graphene-dielectric bi-layer on a conducting substrate was used in bottom-contact pentacene field-effect transistors that showed ohmic contact and small hysteresis. Our new method will provide a way to fabricate flexible electronic devices simply and inexpensively.

Anomalous Ambipolar Transport of Organic Semiconducting Crystals via Control of Molecular Packing Structures

Organic crystals deposited on 2-dimensional (2D) van der Waals substrates have been widely investigated due to their unprecedented crystal structures and electrical properties. van der Waals interaction between organic molecules and the substrate induces epitaxial growth of high quality organic crystals and their anomalous crystal morphologies. Here, we report on unique ambipolar charge transport of a ???lying-down??? pentacene crystal grown on a 2D hexagonal boron nitride van der Waals substrate. From in-depth analysis on crystal growth behavior and ultraviolet photoemission spectroscopy measurement, it is revealed that the pentacene crystal at the initial growth stage have a lattice-strained packing structure and unique energy band structure with a deep highest occupied molecular orbital level compared to conventional ???standing-up??? crystals. The lattice-strained pentacene few layers enable ambipolar charge transport in field-effect transistors with balanced hole and electron field-effect mobilities. Complementary logic circuits composed of the two identical transistors show clear inverting functionality with a high gain up to 15. The interesting crystal morphology of organic crystals on van der Waals substrates is expected to attract broad attentions on organic/2D interfaces for their electronic applications