Effects of hole self-trapping by polarons on transport and negative bias illumination stress in amorphous-IGZO

The effects of hole injection in amorphous-IGZO is analyzed by means of first-principles calculations. The injection of holes in the valence band tail states leads to their capture as a polaron, with high self-trapping energies (from 0.44 to 1.15 eV). Once formed, they mediate the formation of peroxides and remain localized close to the hole injection source due to the presence of a large diffusion energy barrier (of at least 0.6eV). Their diffusion mechanism can be mediated by the presence of hydrogen. The capture of these holes is correlated with the low off-current observed for a-IGZO transistors, as well as, with the difficulty to obtain a p-type conductivity. The results further support the formation of peroxides as being the root cause of Negative bias illumination stress (NBIS). The strong self-trapping substantially reduces the injection of holes from the contact and limits the creation of peroxides from a direct hole injection. In presence of light, the concentration of holes substantially rises and mediates the creation of peroxides, responsible for NBIS.Comment: 8 pages, 8 figures, to be published in Journal of Applied Physic

A Product of 'His' Time? Exploring the Construct of the Ideal Manager in the Cold War Era

Managers are often measured against an ideal that is treated as a tangible object which is stable across generations. It is the contention of this paper that the ideal manager is, in fact, a social construct that is a product of the political and social context within which it exists. Different periods in time create unique typifications of the construct, and the ideal manager is not independent of its environment. The socially constructed nature of the ideal manager will be illustrated through the analysis of the construct at one specific point in time, the internal Cold War in the years following the Second World War and ending in 1960. While widely studied in most disciplines, the Cold War has been largely ignored in the management literature, and therefore provides us with a unique perspective from which to assess the impact of context on the standard to which managers are held

Conflicting identities and the struggle for organizational legitimacy: the Administrative Sciences Association of Canada

Studying the management of multiple organizational identities while striving for organizational legitimacy, we undertake a critical hermeneutic analysis of the archives of the Administrative Sciences Association of Canada (ASAC) and the context in which the association exists

Origin of multiple memory states in organic ferroelectric field-effect transistors

In this work, we investigate the ferroelectric polarization state in metal-ferroelectric-semiconductor-metal structures and in ferroelectric field-effect transistors (FeFET). Poly(vinylidene fluoride-trifluoroethylene) and pentacene was used as the ferroelectric and semiconductor, respectively. This material combination in a bottom gate—top contact transistor architecture exhibits three reprogrammable memory states by applying appropriate gate voltages. Scanning Kelvin probe microscopy in conjunction with standard electrical characterization techniques reveals the state of the ferroelectric polarization in the three memory states as well as the device operation of the FeFET

Organic RFID Tags

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An embedded interfacial network stabilizes inorganic CsPbI₃ perovskite thin films

The black perovskite phase of CsPbI(3) is promising for optoelectronic applications; however, it is unstable under ambient conditions, transforming within minutes into an optically inactive yellow phase, a fact that has so far prevented its widespread adoption. Here we use coarse photolithography to embed a PbI(2)-based interfacial microstructure into otherwise-unstable CsPbI(3) perovskite thin films and devices. Films fitted with a tessellating microgrid are rendered resistant to moisture-triggered decay and exhibit enhanced long-term stability of the black phase (beyond 2.5 years in a dry environment), due to increasing the phase transition energy barrier and limiting the spread of potential yellow phase formation to structurally isolated domains of the grid. This stabilizing effect is readily achieved at the device level, where unencapsulated CsPbI(3) perovskite photodetectors display ambient-stable operation. These findings provide insights into the nature of phase destabilization in emerging CsPbI(3) perovskite devices and demonstrate an effective stabilization procedure which is entirely orthogonal to existing approaches

Museum activities in dementia care: using visual analog scales to measure subjective wellbeing

Introduction: Previous research has shown that people with dementia and caregivers derive wellbeing-related benefits from viewing art in a group, and that facilitated museum object handling is effective in increasing subjective wellbeing for people with a range of health conditions. The present study quantitatively compared the impact of two museum-based activities and a social activity on the subjective wellbeing of people with dementia and their caregivers. Methods: A quasi-experimental crossover design was used. People with early to middle stage dementia and caregivers (N = 66) participated in museum object handling, a refreshment break and art-viewing in small groups. Visual analogue scales were used to rate subjective wellbeing pre and post each activity. Results: Mixed-design ANOVAs indicated wellbeing significantly increased during the session, irrespective of the order in which the activities were presented. Wellbeing significantly increased from object-handling and art-viewing for those with dementia and caregivers across pooled orders, but did not in the social activity of a refreshment break. An end-of-intervention questionnaire indicated that experiences of the session were positive. Conclusion: Results provide a rationale for considering museum activities as part of a broader psychosocial, relational approach to dementia care and support the use of easy to administer visual analogue scales as a quantitative outcome measure. Further partnership working is also supported between museums and healthcare professionals in the development of non-clinical, community-based programmes for this population

History and the obfuscation of Canadian management theory

Although a distinct country from the United States, with different management challenges and opportunities, management theory as taught in Canada is a US-centric body of research that is considered scientific, rational, and context-free. We present a case for understanding management practice in Canada and the importance of developing a theory of management that accounts for the Canadian context