Highly efficient silicon nanoarray solar cells by a single-step plasma-based process

Highly efficient solar cells (conversion efficiency 11.9%, fill factor 70%) based on the vertically aligned single-crystalline nanostructures are fabricated without any pre-fabricated p-n junctions in a very simple, single-step process of Si nanoarray formation by etching p-type Si(100) wafers in low-temperature environment-friendly plasmas of argon and hydrogen mixtures.

Single-step, catalyst-free plasma-assisted synthesis and growth mechanism of single-crystalline aluminum nitride nanorods

Synthesis of one-dimensional AlN nanostructures commonly requires high process temperatures (>900 °C), metal catalyst, and hazardous gas/powder precursors. We report on a simple, single-step, catalyst-free, plasma-assisted growth of dense patterns of size-uniform single-crystalline AlN nanorods at a low substrate temperature (∼650 °C) without any catalyst or hazardous precursors. This unusual growth mechanism is based on highly effective plasma dissociation of N2 molecules, localized species precipitation on AlN islands, and reduced diffusion on the nitrogen-rich surface. This approach can also be used to produce other high-aspect-ratio oxide and nitride nanostructures for applications in energy conversion, sensing, and optoelectronics. © 2010 American Institute of Physics.

Single-step, rapid low-temperature synthesis of Si quantum dots embedded in an amorphous SiC matrix in high-density reactive plasmas

A simple, effective and innovative approach based on low-pressure, thermally nonequilibrium, high-density inductively coupled plasmas is proposed to rapidly synthesize Si quantum dots (QDs) embedded in an amorphous SiC (a-SiC) matrix at a low substrate temperature and without any commonly used hydrogen dilution. The experimental results clearly demonstrate that uniform crystalline Si QDs with a size of 3-4 nm embedded in the silicon-rich (carbon content up to 10.7at.%) a-SiC matrix can be formed from the reactive mixture of silane and methane gases, with high growth rates of ∼1.27-2.34 nm s-1 and at a low substrate temperature of 200 °C. The achievement of the high-rate growth of Si QDs embedded in the a-SiC without any commonly used hydrogen dilution is discussed based on the unique properties of the inductively coupled plasma-based process. This work is particularly important for the development of the all-Si tandem cell-based third generation photovoltaic solar cells.

From nucleation to nanowires : a single-step process in reactive plasmas

This feature article introduces a deterministic approach for the rapid, single-step, direct synthesis of metal oxide nanowires. This approach is based on the exposure of thin metal samples to reactive oxygen plasmas and does not require any intervening processing or external substrate heating. The critical roles of the reactive oxygen plasmas, surface processes, and plasma-surface interactions that enable this growth are critically examined by using a deterministic viewpoint. The essentials of the experimental procedures and reactor design are presented and related to the key process requirements. The nucleation and growth kinetics is discussed for typical solid-liquid-solid and vapor-solid-solid mechanisms related to the synthesis of the oxide nanowires of metals with low (Ga, Cd) and high (Fe) melting points, respectively. Numerical simulations are focused on the possibility to predict the nanowire nucleation points through the interaction of the plasma radicals and ions with the nanoscale morphological features on the surface, as well as to control the localized 'hot spots' that in turn determine the nanowire size and shape. This generic approach can be applied to virtually any oxide nanoscale system and further confirms the applicability of the plasma nanoscience approaches for deterministic nanoscale synthesis and processing.

Single-step synthesis and magnetic separation of graphene and carbon nanotubes in arc discharge plasmas

The unique properties of graphene and carbon nanotubes made them the most promising nanomaterials attracting enormous attention, due to the prospects for applications in various nanodevices, from nanoelectronics to sensors and energy conversion devices. Here we report on a novel deterministic, single-step approach to simultaneous production and magnetic separation of graphene flakes and carbon nanotubes in an arc discharge by splitting the high-temperature growth and low-temperature separation zones using a non-uniform magnetic field and tailor-designed catalyst alloy, and depositing nanotubes and graphene in different areas. Our results are very relevant to the development of commercially-viable, single-step production of bulk amounts of high-quality graphene.

Self-action of high-frequency surface waves in a magnetoactive planar plasma waveguide

The self-modulation process of a high-frequency surface wave (SW) in a wave-guiding structure - a semibounded magnetoactive plasma and perfectly conducting metal wall - is considered for the weak nonlinearity approximation. Estimates are given for the contributions to the nonlinear frequency shift of the SW from the two principal self-action channels: via the generation of a signal of the doubled frequency and of static surface perturbations, arising as the result of the action of a ponderomotive force. Solutions for the field envelope of the nonlinear wave are examined with regard to their stability with respect to longitudinal and transverse perturbations.

Reconceptualizing digital service quality : a call-to-action and research approach

The nature of services and service delivery has been changing rapidly since the 1980’s when many seminal papers in services research were published. Services are increasingly digital, or have a digital component. Further, a large and heterogeneous literature, with competing and overlapping definitions, many of which are dated and inappropriate to contemporary digital services offerings is impeding progress in digital services research. In this conceptual paper, we offer a critical review of some existing conceptualizations of services and digital services. We argue that an inductive approach to understanding cognition about digital services is required to develop a taxonomy of digital services and a new vocabulary. We argue that this is a pre-requisite to theorizing about digital services, including understanding quality drivers, value propositions, and quality determinants for different digital service types. We propose a research approach for reconceptualising digital services and service quality, and outline methodological approaches and outcomes.

Design research for the real world : a design-led innovation model for action research

The aim of this paper is to aid researchers in undertaking action research within industry with a particular focus on the study of design-led innovation. This paper presents the research design of a case study shaped to solve real world problems concerning a major Australian Airport Corporation by bridging the chasm between academia and industry. The researcher’s role is one of design-innovation catalyst, facilitating the integration of design as a new strategic capability and innovation approach within an organisation’s fabric. A discussion of the researcher experience within industry will provide evidence on the challenges facing such a research role, with strategies for overcoming these barriers presented. Based on the authors’ experience as a researcher within industry and reflection within practice, a project progression model for action research is presented to enable the improved management of industry based research.

The 1989 Comprehensive Plan of Action (CPA) and refugee policy in Southeast Asia : twenty years forward what has changed?

In 2012, the only South East Asian countries that have ratified the 1951 Convention relating to the Status of Refugees and the 1967 Protocol Relating to the Status of Refugees (hereafter referred to as the 1951 Convention and 1967 Protocol) is Philippines (signed 1954), Cambodia (signed 1995) and Timor Leste (signed 2001). Countries such as Indonesia, Malaysia and Thailand have annual asylum seeking populations from Myanmar, South Asia and Middle East, that are estimated to be at 15 000-20 000 per country (UNHCR 2012). The lack of a permanent and formal asylum processing process in these countries means that that asylum-seeking populations in the region are reliant on the local offices of the United Nations High Commission for Refugees based in the region to process their claims. These offices rely upon the good will of these governments to have a presence near detection camps and in capital cities to process claims of those who manage to reach the UNHCR representative office. The only burden sharing mechanism within the region primarily exists under the Bali Process on People Smuggling, Trafficking in Persons and Related Transnational Crime (the Bali Process), introduced in 2002. The Bali Process refers to an informal cooperative agreement amongst the states from the Asia-Pacific region, with Australia and Indonesia as the co-chairs, which discusses its namesake: primarily anti-people smuggling activities and migration protocols. There is no provision within this process to discuss the development of national asylum seeking legislation, processes for domestic processing of asylum claims or burden sharing in contrast to other regions such as Africa and South America (i.e. 2009 African Union Convention for the Protection and Assistance of the Internally Displaced, 1969 African Union Convention Governing the Specific Aspects of Refugee Problems in Africa and 1984 Cartagena Declaration on Refugees [Americas]) (PEF 2010: 19).

Social water assessment protocol : a step towards connecting mining, water and human rights

The human right to water has recently been recognised by both the United Nations General Assembly and the Human Rights Council. As the mining industry interacts with water on multiple levels, it is important that these interactions respect the human right to water. Currently, a disconnect exists between mine site water management practices and the recognition of water from a human rights perspective. The Minerals Council of Australia (MCA) Water Accounting Framework (WAF) has previously been used to strengthen the connection between water management and human rights. This article extends this connection through the use of a Social Water Assessment Protocol (SWAP). The SWAP is scoping tool consisting of a set of questions classified into taxonomic themes under leading topics with suggested sources of data that enable mine sites to better understand the local water context in which they operate. Three of the themes contained in the SWAP – gender, Indigenous peoples and health – are discussed to demonstrate how the protocol may be useful in assisting mining companies to consider their impacts on the human right to water.

Health education action research (HEAR) framework

As a mandatory assessment technique of the Health Education Senior Syllabus (QSA, 2010), action research provides an opportunity for unique insights into health related knowledge, behaviours, beliefs, attitudes and values. It has the potential to be a very motivating and engaging form of learning and assessment. Despite these benefits, action research can be a daunting prospect for some students and a challenging form of assessment for teachers to conceptualise and construct. Session participants will be provided with a visual framework for understanding, structuring and sequencing action research projects. This framework will present a series of action research phases and map them against the four general objectives and three assessable dimensions of the syllabus (QSA, 2010. Participants are strongly encouraged to bring a copy of the syllabus for reference and use during this session. Reference Queensland Studies Authority. (2010). Health Education Senior Syllabus 2010. Brisbane: QSA.

One-step macroscopic alignment of conjugated polymer systems by epitaxial crystallization during spin-coating

The one-step preparation of highly anisotropic polymer semiconductor thin films directly from solution is demonstrated. The conjugated polymer poly(3-hexylthiophene) (P3HT) as well as P3HT:fullerene bulk-heterojunction blends can be spin-coated from a mixture of the crystallizable solvent 1,3,5-trichlorobenzene (TCB) and a second carrier solvent such as chlorobenzene. Solidification is initiated by growth of macroscopic TCB spherulites followed by epitaxial crystallization of P3HT on TCB crystals. Subsequent sublimation of TCB leaves behind a replica of the original TCB spherulites. Thus, highly ordered thin films are obtained, which feature square-centimeter-sized domains that are composed of one spherulite-like structure each. A combination of optical microscopy and polarized photoluminescence spectroscopy reveals radial alignment of the polymer backbone in case of P3HT, whereas P3HT:fullerene blends display a tangential orientation with respect to the center of spherulite-like structures. Moreover, grazing-incidence wide-angle X-ray scattering reveals an increased relative degree of crystallinity and predominantly flat-on conformation of P3HT crystallites in the blend. The use of other processing methods such as dip-coating is also feasible and offers uniaxial orientation of the macromolecule. Finally, the applicability of this method to a variety of other semi-crystalline conjugated polymer systems is established. Those include other poly(3-alkylthiophene)s, two polyfluorenes, the low band-gap polymer PCPDTBT, a diketopyrrolopyrrole (DPP) small molecule as well as a number of polymer:fullerene and polymer:polymer blends. Macroscopic spherulite-like structures of the conjugated polymer poly(3-hexylthiophene) (P3HT) grow directly during spin-coating. This is achieved by processing P3HT or P3HT:fullerene bulk heterojunction blends from a mixture of the crystallizable solvent 1,3,5-trichlorobenzene and a second carrier solvent such as chlorobenzene. Epitaxial growth of the polymer on solidified solvent crystals gives rise to circular-symmetric, spherulite-like structures that feature a high degree of anisotropy.

Contributions of the private sector to global biodiversity protection: case study of the Fortune 500 companies

Since the inception of the UN Convention on Biological Diversity (CBD) in 1992, little progress has been achieved in terms of involving the business community in protecting biological diversity worldwide. This article assesses the current activities of US Fortune 500 companies with respect to global biodiversity protection and the goals of the CBD. Data and information collected from 500 companies within eight major industrial sectors were further categorized at the company level to assess each company's involvement in global biodiversity protection. Our findings show that although companies' business profiles highly influence their decision-making process regarding the adoption of biodiversity protection policies and measures, their revenue profiles are less influential. We show that despite generating low revenues, companies in the utility sector are more active in the adoption of biodiversity protection policy than those in the financial sector, which generate high revenues. This study also demonstrates that companies must be convinced of the major effects of biodiversity loss on their bottom lines to be motivated to protect biological diversity. Companies' business and business-related risk profiles can also influence the adoption of biodiversity protection policies within the company. The study further demonstrates that a measurable biodiversity impact indicator is necessary for the companies to get seriously involved in the mitigation action. Finally, this study proposes a three-step biodiversity loss mitigation action framework that is drawn upon the assessment of the 500 companies that can contribute to develop an elaborative framework of business sector-specific mitigation plan. © 2013 Copyright Taylor and Francis Group, LLC.