ANALYZING BEST PRACTICE AND CRITICAL SUCCESS FACTORS IN A HEALTH INFORMATION SYSTEM CASE – ARE THERE ANY SHORTCUTS TO SUCCESSFUL IT IMPLEMENTATION?

This paper discusses critical success factors (CSF) and best practice in relation to IT implementation in the health sector. We have studied a University Hospital’s implementation of a health information system (HIS) and particularly one clinic which implementation process was described as very successful compared to other units at this hospital. The purpose of the paper is to gain further understanding of if and how well CSFs and best practice solutions can explain this successful case. We do this in order to explore if CSFs and best practice offer any shortcuts to successful IT implementation. By understanding the reasons behind this case’s success we can identify if CSFs and best practice potentially can explain the success, or if there are other explanations in this case. Based on our findings we discuss and question the sometimes overestimated belief in CSFs and best practice as shortcuts to success performance. An important contribution from this study is that situational and contextual factors are very critical to understand and acknowledge during HIS implementations

Managing The Development Of Secure Identification - Investigating A National e-ID Initiative Within A Public e-Service Context

This paper investigates the management of developing electronic identification (e-ID) within a public e-service context. e-ID is an important key enabler for secure identification, authentication and digital signing via the Internet and a part of e-service design. As users, and citizens, we become reliant on electronic solutions that give us a certain level of utility and trust, and use e-ID solutions to interact with local and central government in an e-service context. The management of e-ID development in a national context is the case in focus for investigation. Such development initiatives, and especially inter-organizational projects, face a number of challenges. Therefore it is a need for a more thorough understanding of e-ID development within a public e-service context. The purpose is to analyse the contemporary management of e-ID development in Sweden from: a) an e-government systems development life-cycle perspective and b) a project challenge and critical success factor perspective. This study concludes that there are significant challenges involved in managing integrated e-ID development. Challenges involve the organization and management of the program and can be traced back to e-government and general project management literature, but based on this study one can question, e.g. governance models, centralization, and a narrow focus on a technical artefact. Important implications from this paper are a call for further contextual studies of e-ID development, putting the user and organizational setting, path dependency, and governance models in focus.FUSe - Future Safe Electronic Identificatio

Coupling light into thin silicon layers for high-efficiency solar cells

Thin-film solar cells based on amorphous and microcrystalline silicon require thin photoactive layers to ensure a satisfactory collection of the photogenerated carriers. The small thickness is advantageous in terms of raw material consumption and industrial throughput but results in poor light absorption at long wavelengths. Most of the time, textured substrates are used for the deposition of solar cells inducing scattering of light and increased light absorption in the silicon layer which enhance the short-circuit current density (Jsc) but also inducing the growth of silicon layers with defects that limit the open-circuit voltage (Voc) and the fill factor (F F ). Therefore, a major challenge is the design and realisation of structures that allow proper growth of the material while providing efficient light coupling. In a first part of this thesis a better understanding of the light in-coupling mechanism via interface textures is achieved. Angle- and polarisation-resolved analysis of the external quantum efficiency of a cell grown on a one-dimensional grating structure demonstrates that light management can be viewed as the excitation of guided modes that are supported by the silicon layers. Defined peaks of enhanced photocurrent in the weakly absorbing region were observed for this cell, and these absorption phenomena were related to dispersion curves calculated for guided-modes in an equivalent flat multilayer system. This allows an intuitive understanding of photocurrent enhancement via interface texturing and provides new insights into the features that are required for efficient light trapping. Then, a novel means of substrate texturing was required in order to emancipate the thin-film silicon solar cells from the standard textures used for light management, and open the road for the implementation of novel photonic designs that improve light trapping in high-efficiency devices. To achieve both of these goals, the replication of textures by UV nano-imprinting was investigated and developed. The remarkable replication fidelity obtained is such that the original texture cannot be distinguished from the replicated one by measurements such as atomic force microscopy and scanning electron microscopy. Solar cell efficiencies as high as on standard electrodes were demonstrated by texturing both plastic substrates for the n-i-p configuration and glass substrates for both the n-i-p and p-i-n configurations. In addition, the nano-imprinting process enabled the development of a novel tool called nanomoulding which permits the selected shaping of the surface of zinc oxide layers. Furthermore, it was observed that nano-imprinting of micro-metric features at the front of n-i-p and p-i-n devices boosts the Jsc by more than 4% by providing an anti-reflection effect. The manifold applications which use UV nano-imprinting in this thesis show its extraordinary versatility and demonstrate that it is a suitable experimental platform for thin-film silicon solar cells. The reduction of parasitic absorption in inactive layers is another means to enhance Jsc and solar cell efficiency. Therefore, parasitic absorption that takes place in rough metallic back reflectors which are commonly used in the n-i-p configuration is investigated and reduced. It is shown that the addition of a zinc oxide buffer layer of optimal thickness between the metallic layer and the silicon layers helps to mitigate parasitic absorption both in the metal and in the adjacent doped layer. Then, parasitic absorption related to the quality of the silver back reflector when deposited on rough nano-textures was reduced using a thermal annealing at low temperature. The combination of texturing on plastic by UV nano-imprinting with the deposition of a high-quality silver reflector led to a flexible a-Si:H/a-Si:H device with remarkable initial and stable efficiencies of 11.1% and 9.2%, respectively, using less than half a micron of silicon. Eventually, to circumvent the strong limitation of Voc and F F due to the defective growth of silicon on textured substrates, a novel type of substrate was realised and studied. This substrate decouples the optically rough interface that allows high Jsc, from the growth surface which is made flat to allow the growth of devices with good-quality silicon and high Voc and F F . Triple-junction n-i-p a-Si:H/μc-Si:H/μc-Si:H solar cells were realised on this substrate, and a stable efficiency of 13% was obtained, which is the highest stable efficiency reported so far for thin-film silicon solar cells by our laboratory. This novel approach is very promising as it demonstrates that the usual morphology trade-off can be overcome through the use of a single flat light-scattering substrate that fulfills all the requirements to push even further thin-film silicon solar cell efficiencies. To conclude, this thesis brought improvements both in understanding and in devices. A better understanding of the features required for efficient light coupling was first found by showing that light coupling via interface texturing is due to the excitation of guided modes. Then it was demonstrated that UV nano-imprinting allows the introduction of novel photonic designs for better light management in high-efficiency solar cells and also allows the introduction of textures suitable for efficient light management on different substrates. This is illustrated by the flexible a-Si:H/a-Si:H device exhibiting 9.2% stable efficiency on a plastic which is, to the knowledge of the author, the highest reported efficiency for a-Si:H on plastic substrate. Also, novel flat light-scattering substrates which allow the growth of excellent material quality were developed and introduced in solar cells. This led to the realisation triple-junction n-i-p solar cell with a record stable efficiency of 13% that is close to the current world record of 13.4% reported in 2012 by LG Solar using the p-i-n configuration

Angular behavior of the absorption limit in thin film silicon solar cells

We investigate the angular behavior of the upper bound of absorption provided by the guided modes in thin film solar cells. We show that the 4n^2 limit can be potentially exceeded in a wide angular and wavelength range using two-dimensional periodic thin film structures. Two models are used to estimate the absorption enhancement; in the first one, we apply the periodicity condition along the thickness of the thin film structure but in the second one, we consider imperfect confinement of the wave to the device. To extract the guided modes, we use an automatized procedure which is established in this work. Through examples, we show that from the optical point of view, thin film structures have a high potential to be improved by changing their shape. Also, we discuss the nature of different optical resonances which can be potentially used to enhance light trapping in the solar cell. We investigate the two different polarization directions for one-dimensional gratings and we show that the transverse magnetic polarization can provide higher values of absorption enhancement. We also propose a way to reduce the angular dependence of the solar cell efficiency by the appropriate choice of periodic pattern. Finally, to get more practical values for the absorption enhancement, we consider the effect of parasitic loss which can significantly reduce the enhancement factor

Resonant absorption enhancement in solar cells with periodically textured interfaces

We use a 1D grating back reflector to study the mechanism of light trapping in solar cells. Experimental results of a full solar cell on a sinusoidal back reflector are compared to a theoretical model using an expansion into grating modes and the Rayleigh hypothesis. By means of the sinusoidal shape, the continuity equations extend the coupling only to neighboring orders. The essential aspects of the coupling process are thus included, but the algorithm requires only a minimum amount of mathematical complexity. Our modeling results correctly reproduce the absorption of the periodically textured solar cell for both polarization directions. The absorption phenomena underlying the light trapping process can thus be studied with a small number of parameters like period, depth, and film thickness

Excitation of guided-mode resonances in thin film silicon solar cells

Thin film silicon solar cells are attractive for photovoltaics; however, the poor charge transport in this material requires that the devices are thinner than the absorption length. Adequate absorption can nevertheless be achieved by light scattering at textured interfaces because light can get trapped inside the absorber layer if it is scattered into angles above the critical angle of total internal reflection. This situation can be identified with the propagation of a guided mode in a waveguide where silicon plays the role of the high index guiding medium and the interface texture serves to couple the incident light to modes via grating coupling. We present an experimental realization of a solar cell structure on a line grating where the enhanced photocurrent can be clearly related to resonant excitation of waveguide modes

Electrically flat/optically rough substrates for efficiencies above 10% in n-i-p thin-film silicon solar cells

Substrates with extremely low roughness to allow the growth of good-quality silicon material but that nevertheless present high light trapping properties are presented. In a first application, silver reflectors are used in single and tandem-junction amorphous silicon (a-Si:H) solar cells. High initial (stable) efficiencies of 10.4 % (8.1 %) for single-junction a-Si:H cells on glass and 11.1 % (9.2 %) for tandem-junction a-Si:H/a-Si:H cells on plastic are obtained. A second application better suited to multi-junction solar cells based on microcrystalline silicon (μc-Si:H) solar cells is presented: the substrate consists of rough zinc oxide (ZnO) grown on a flat silver reflector which is covered with a-Si:H; polishing of this structure yields an a-Si:H/ZnO interface that provides high light scattering even though the cell is deposited on a flat interface. We present results of ~ 4-μm-thick μc-Si:H solar cells prepared on such substrates with high open-circuit voltages of 520 mV. A large relative efficiency gain of 20% is observed compared to a co-deposited cell grown directly on an optimized textured substrate

Enniatin B and beauvericin affect intestinal cell function and hematological processes in Atlantic salmon (Salmo salar) after acute exposure

Unintentional use of mold-infested plant-based feed ingredients are sources of mycotoxins in fish feeds. The presence of the emerging mycotoxins ENNB and BEA in Norwegian commercial fish feeds and plant-based feed ingredients has raised concerns regarding the health effects on farmed Atlantic salmon (Salmon salar). Atlantic salmon pre-smolts were exposed to non-lethal doses of BEA and ENNB (ctrl, 50 and 500 μg/kg feed for 12 h), after which total RNA sequencing of the intestine and liver was carried out to evaluate gut health and identify possible hepatological changes after acute dietary exposure. ENNB and BEA did not trigger acute toxicity, however ENNB caused the onset of pathways linked to acute intestinal inflammation and BEA exposures caused the onset of hepatic hematological disruption. The prevalence and concentration of ENNB found in today's commercial feed could affect the fish health if consumed over a longer time-period.publishedVersio

High fidelity transfer of nanometric random textures by UV embossing for thin film solar cells applications

We investigate the transfer of random nanostructures commonly used in thin film silicon solar cells onto inexpensive substrates, such as glass or flexible polyethylene sheets. Morphological and optical analyses of masters and replicas show the successful transfer of details with sizes much below 1 m. These high-quality replicas are obtained by UV nano-imprinting, avoiding the use of PDMS as intermediate mold which has been identified as being responsible for the lack of resolution found in previous works

Understanding of photocurrent enhancement in real thin film solar cells: towards optimal onedimensional gratings

Despite the progress in the engineering of structures to enhance photocurrent in thin film solar cells, there are few comprehensive studies which provide general and intuitive insight into the problem of light trapping. Also, lack of theoretical propositions which are consistent with fabrication is an issue to be improved. We investigate a real thin film solar cell with almost conformal layers grown on a 1D grating metallic backreflector both experimentally and theoretically. Photocurrent increase is observed as an outcome of guided mode excitation in both theory and experiment by obtaining the external quantum efficiency of the cell for different angles of incidence and in both polarization directions. Finally, the effect of geometrical parameters on the short circuit current density of the device is investigated by considering different substrate shapes that are compatible with solar cell fabrication. Based on our simulations, among the investigated shapes, triangular gratings with a very sharp slope in one side, so called sawtooth gratings, are the most promising 1D gratings for optimal light trapping