Point defect segregation and its role in the detrimental nature of Frank partials in Cu(In,Ga)Se2 thin-film absorbers

The interaction of point defects with extrinsic Frank loops in the photovoltaic absorber material Cu(In,Ga)Se₂ was studied by aberration-corrected scanning transmission electron microscopy in combination with electron energy-loss spectroscopy and calculations based on density-functional theory. We find that Cu accumulation occurs outside of the dislocation cores bounding the stacking fault due to strain-induced preferential formation of Cu‾²In, which can be considered a harmful hole trap in Cu(In,Ga)Se₂. In the core region of the cation-containing α-core, Cu is found in excess. The calculations reveal that this is because Cu on In-sites is lowering the energy of this dislocation core. Within the Se-containing β-core, in contrast, only a small excess of Cu is observed, which is explained by the fact that Cu¡ⁿ and Cu¡ are the preferred defects inside this core, but their formation energies are positive. The decoration of both cores induces deep defect states, which enhance nonradiative recombination. Thus, the annihilation of Frank loops during the Cu(In,Ga)Se₂ growth is essential in order to obtain absorbers with high conversion efficiencies

Perception of the primary health care response capacity by patients with and without mental health problems, and health professionals: qualitative study

BACKGROUND: The objective of this study is to deepen our understanding of perceptions towards Primary Health Care Response Capacity by specifically using patients with and without mental disorders, as well as family doctors and a manager, in order to compare and endorse perspectives. For it, a qualitative study was performed. In-depth interviews were conducted with 28 patients with and without mental health disorders and focus groups were held with 21 professionals and a manager. An inductive thematic content analysis was performed in order to explore, develop and define the emergent categories of analysis. RESULTS: The fundamental domains for patients are dignity, communication, and rapid service. People with mental health problems also highlight the domain of confidentiality as relevant, while patients who do not have a mental health problem prioritize the domain of autonomy. Patients with mental health disorders report a greater number of negative experiences in relation to the domain of dignity. Patients do not consider their negative experiences to be a structural problem of the system. These findings are also endorsed by health care professionals. CONCLUSIONS: It is necessary to take these results into account as responsive systems can improve service uptake, ensure adherence to treatment, and ultimately enhance patient welfare

Dependence of phase transitions on halide ratio in inorganic CsPb BrxI1 x 3 perovskite thin films obtained from high throughput experimentation

In this communication, we present the phase diagram of CsPb BrxI1 amp; 8722;x 3 0 amp; 8804; x amp; 8804; 1, 300 585 K obtained by high throughput in situ GIWAXS measurements of a combinatorial thin film library. We find that all compositions convert to the cubic perovskite phase at high temperature and that the presence of bromide in the films stabilizes the metastable perovskite phases upon cool down. In accordance with recent predictions from DFT calculations, the transition temperatures monotonically decrease with increasing bromide conten

General practitioners' experience and benefits from patient evaluations

<p>Abstract</p> <p>Background</p> <p>It has now for many years been recognised that patient evaluations should be undertaken as an integral part of the complex task of improving the quality of general practice care. Yet little is known about the general practitioners' (GPs') benefit from patient evaluations. Aim 1 was to study the impact on the GPs of a patient evaluation and subsequent feedback of results presented at a plenary session comprising a study guide for the results and group discussions. Aim 2 was to study possible facilitators and barriers to the implementations of the results raised by the patient evaluation process.</p> <p>Methods</p> <p>A patient evaluation survey of 597 voluntarily participating GPs was performed by means of the EUROPEP questionnaire. Evaluation results were fed back to the GPs as written reports at a single feedback meeting with group discussions of the results. Between 3 and 17 months after the feedback, the 597 GPs received a questionnaire with items addressing their experience with and perceived benefit from the evaluations.</p> <p>Results</p> <p>79.4% of the GPs responded. 33% of the responding GPs reported that the patient evaluation had raised their attention to the patient perspective on the quality of general practice care. Job satisfaction had improved among 26%, and 21% had developed a more positive attitude to patient evaluations. 77% of the GPs reported having learnt from the evaluation. 54% had made changes to improve practice, 82% would recommend a patient evaluation to a colleague and 75% would do another patient evaluation if invited. 14% of the GPs had become less positive towards patient evaluations, and job satisfaction had decreased among 3%.</p> <p>Conclusions</p> <p>We found a significant impact on the GPs regarding satisfaction with the process and attitude towards patient evaluations, GPs' attention to the patients' perspective on care quality and their job satisfaction. Being benchmarked against the average seemed to raise barriers to the concept of patient evaluations and difficulties interpreting the results may have formed a barrier to their implementation which was partly overcome by adding qualitative data to the quantitative results. The GPs' significant willingness to share and discuss the results with others may have served as a facilitator.</p

Elemental redistributions at structural defects in Cu(In,Ga)Se₂ thin films for solar cells

The microstructural evolution of Cu(In,Ga)Se2 absorber layers during a three-stage-type co-evaporation process was studied to elucidate the effect of a Cu-rich stage on the formation of extended structural defects. Defect densities for two Cu-poor samples, one interrupted before and one after this crucial Cu-rich composition stage, were investigated by scanning transmission electron microscopy (STEM) imaging. The structure and chemical nature of individual defects were investigated by aberration-corrected high-resolution STEM in combination with electron energy-loss spectroscopy on the atomic-scale. In spite of the different defect densities between the two samples, most of the individual defects exhibited similar chemistry. In particular, the elemental distributions of atomic columns at {112} twin planes, which are very frequent in Cu(In,Ga)Se2 thin films, were found to be the same as in the defect-free grain interiors. In contrast, within grain boundaries, dislocation cores, and other structurally more complex defects, elemental redistributions of Cu and In were observed