On improvements in metal oxide based flexible transistors through systematic evaluation of material properties

Thin-film metal oxide (MOx) semiconductors have opened the way to a new generation of electronics based on their unique properties. With mobilities, mu, of up to 80 cm2V-1s-1, metal oxides do not rival crystalline silicon (mu~1000 cm2V-1s-1) for complex applications. But such oxides do have three unique characteristics driving great interest: their mobilities persist in the amorphous form, contrary to the thousandfold drop seen in silicon; they are transparent; and they can be processed at, or near, room temperature. Most work on MOx semiconductors, in particular indium gallium zinc oxide (IGZO), has focused on display applications, where MOx thin-film transistors (TFTs) are used to drive individual pixels, reducing power consumption by blocking less light than alternatives, and allowing smaller pixels due to reduced TFT sizes. Such work has seen great advances in IGZO, but has generally not considered the thermal budget during production. By utilising the low temperature processing possible with MOx, a new world of applications becomes possible: flexible electronics. This work aims to improve the characteristics of TFTs based on amorphous IGZO (a-IGZO) through detailed study of the thin-film structure in relation to functional performance, looking at the material structure of three critical layers in an a-IGZO TFT. A study of optimisation of a dielectric layer of Al2O3, deposited by atomic layer deposition (ALD), is presented. This dielectric, between the a-IGZO and the gate electrode, shows a three-layer substructure in what has previously been regarded as a single homogeneous layer. A study of the insulating Al2O3 buffer layer below the a-IGZO compared the properties of Al2O3 deposited by ALD and sputtering. Sputtered material has a more complex structure than ALD, consisting of multiple sublayers that correlate with the sputtering process. The structure of the two materials is discussed, and the impact on device performance considered. A detailed systematic study of the effects of annealing of a-IGZO shows a strong dependence of the density on both time and temperature. A two mechanism model is proposed which consists of structural relaxation of the amorphous material followed by absorption of oxygen from the environment. Finally, investigation of the influence of the buffer material on the a-IGZO, and the structure of this interface showed little difference in the growth of the a-IGZO, but did reveal some changes in the interface, while a systematic study of annealing effects on the a-IGZO-dielectric interface showed some interesting changes in this structure, both of which are likely to significantly impact the operational characteristics of TFT devices

Investigation of SARS-CoV-2 faecal shedding in the community: a prospective household cohort study (COVID-LIV) in the UK

Background SARS-CoV-2 is frequently shed in the stool of patients hospitalised with COVID-19. The extent of faecal shedding of SARS-CoV-2 among individuals in the community, and its potential to contribute to spread of disease, is unknown. Methods In this prospective, observational cohort study among households in Liverpool, UK, participants underwent weekly nasal/throat swabbing to detect SARS-CoV-2 virus, over a 12-week period from enrolment starting July 2020. Participants that tested positive for SARS-CoV-2 were asked to provide a stool sample three and 14 days later. In addition, in October and November 2020, during a period of high community transmission, stool sampling was undertaken to determine the prevalence of SARS-CoV-2 faecal shedding among all study participants. SARS-CoV-2 RNA was detected using Real-Time PCR. Results A total of 434 participants from 176 households were enrolled. Eighteen participants (4.2%: 95% confidence interval [CI] 2.5–6.5%) tested positive for SARS-CoV-2 virus on nasal/throat swabs and of these, 3/17 (18%: 95% CI 4–43%) had SARS-CoV-2 detected in stool. Two of three participants demonstrated ongoing faecal shedding of SARS-CoV-2, without gastrointestinal symptoms, after testing negative for SARS-CoV-2 in respiratory samples. Among 165/434 participants without SARS-CoV-2 infection and who took part in the prevalence study, none had SARS-CoV-2 in stool. There was no demonstrable household transmission of SARS-CoV-2 among households containing a participant with faecal shedding. Conclusions Faecal shedding of SARS-CoV-2 occurred among community participants with confirmed SARS-CoV-2 infection. However, during a period of high community transmission, faecal shedding of SARS-CoV-2 was not detected among participants without SARS-CoV-2 infection. It is unlikely that the faecal-oral route plays a significant role in household and community transmission of SARS-CoV-2

Design, Fabrication and Characterisation of Multi-Parameter Optical Sensors Dedicated to E-Skin Applications.

For many years there has been a strong research interest in soft electronics for artificial skin applications. However, one challenge with stretchable devices is the limited availability of high performance, stretchable, electrical conductors and semiconductors that remain stable under strain. Examples of such electronic skin require excessive amounts of wires to address each sensing element-compression force and strain-in a conventional matrix structure. Here, we present a new process for fabricating artificial skin consisting of an optical waveguide architecture, enabling wide ranging sensitivity to external mechanical compression and strain. The manufacturing process allows design of a fully stretchable polydimethylsiloxane elastomer waveguide with embedded gratings, replicated from low cost DVD-Rs. This optical artificial skin allows the detection of compression forces from 0 to 3.8 N with controllable sensitivity. It also permits monitoring of elongation deformations up to 135%. This type of stretchable optical sensor is highly robust, transparent, and presents a large sensing area while limiting the amount of wires connecting to the sensor. Thus, this optical artificial skin presents far superior mechanical properties compared to current electronic skin

Religion and the Unmaking of Prejudice toward Muslims: Evidence from a Large National Sample

<div><p>In the West, anti-Muslim sentiments are widespread. It has been theorized that inter-religious tensions fuel anti-Muslim prejudice, yet previous attempts to isolate sectarian motives have been inconclusive. Factors contributing to ambiguous results are: (1) failures to assess and adjust for multi-level denomination effects; (2) inattention to demographic covariates; (3) inadequate methods for comparing anti-Muslim prejudice relative to other minority group prejudices; and (4) <i>ad hoc</i> theories for the mechanisms that underpin prejudice and tolerance. Here we investigate anti-Muslim prejudice using a large national sample of non-Muslim New Zealanders (<i>N</i> = 13,955) who responded to the 2013 New Zealand Attitudes and Values Study. We address previous shortcomings by: (1) building Bayesian multivariate, multi-level regression models with denominations modeled as random effects; (2) including high-resolution demographic information that adjusts for factors known to influence prejudice; (3) simultaneously evaluating the relative strength of anti-Muslim prejudice by comparing it to anti-Arab prejudice and anti-immigrant prejudice within the same statistical model; and (4) testing predictions derived from the Evolutionary Lag Theory of religious prejudice and tolerance. This theory predicts that in countries such as New Zealand, with historically low levels of conflict, religion will tend to increase tolerance generally, and extend to minority religious groups. Results show that anti-Muslim and anti-Arab sentiments are confounded, widespread, and substantially higher than anti-immigrant sentiments. In support of the theory, the intensity of religious commitments was associated with a general increase in tolerance toward minority groups, including a poorly tolerated religious minority group: Muslims. Results clarify religion’s power to enhance tolerance in peaceful societies that are nevertheless afflicted by prejudice.</p></div

MCMC Solutions: Warmth to Arabs, Muslims, Immigrants.

<p>MCMC Solutions: Warmth to Arabs, Muslims, Immigrants.</p

Predictors of Tolerance toward Immigrants, Arabs and Muslims.

<p>Predictors of Tolerance toward Immigrants, Arabs and Muslims.</p

Residual Variance Structure (R-Structure units).

<p>Residual Variance Structure (R-Structure units).</p