Solar Trees: First Large-Scale Demonstration of Fully Solution Coated, Semitransparent, Flexible Organic Photovoltaic Modules.

The technology behind a large area array of flexible solar cells with a unique design and semitransparent blue appearance is presented. These modules are implemented in a solar tree installation at the German pavilion in the EXPO2015 in Milan/IT. The modules show power conversion efficiencies of 4.5% and are produced exclusively using standard printing techniques for large-scale production.

Formative Evaluation to Assess Communication Technology Access and Health Communication Preferences of Alaska Native People.

OBJECTIVE: Information technology can improve the quality, safety, and efficiency of healthcare delivery by improving provider and patient access to health information. We conducted a nonrandomized, cross-sectional, self-report survey to determine whether Alaska Native and American Indian (AN/AI) people have access to the health communication technologies available through a patient-centered medical home. METHODS: In 2011, we administered a self-report survey in an urban, tribally owned and operated primary care center serving AN/AI adults. Patients in the center's waiting rooms completed the survey on paper; center staff completed it electronically. RESULTS: Approximately 98% (n = 654) of respondents reported computer access, 97% (n = 650) email access, and 94% (n = 631) mobile phone use. Among mobile phone users, 60% had Internet access through their phones. Rates of computer access (p = .011) and email use (p = .005) were higher among women than men, but we found no significant gender difference in mobile phone access to the Internet or text messaging. Respondents in the oldest age category (65-80 years of age) were significantly less likely to anticipate using the Internet to schedule appointments, refill medications, or communicate with their health care providers (all p < .001). CONCLUSION: Information on use of health communication technologies enables administrators to deploy these technologies more efficiently to address health concerns in AN/AI communities. Our results will drive future research on health communication for chronic disease screening and health management.

Medical home implementation and trends in diabetes quality measures for AN/AI primary care patients.

AIMS: Patient-centered medical home (PCMH) principles including provider continuity, coordination of care, and advanced access align with healthcare needs of patients with Type II diabetes mellitus (DM-II). We investigate changes in trend for DM-II quality indicators after PCMH implementation at Southcentral Foundation, a tribal health organization in Alaska. METHODS: Monthly rates of DM-II incidence, hemoglobin A1c (HbA1c) measurements, and service utilization were calculated from electronic health records from 1996 to 2009. We performed interrupted time series analysis to estimate changes in trend. RESULTS: Rates of new DM-II diagnoses were stable prior to (p=0.349) and increased after implementation (p<0.001). DM-II rates of HbA1c screening increased, though not significantly, before (p=0.058) and remained stable after implementation (p=0.969). There was non-significant increasing trend in both periods for percent with average HbA1c less than 7% (53 mmol/mol; p=0.154 and p=0.687, respectively). Number of emergency visits increased before (p<0.001) and decreased after implementation (p<0.001). Number of inpatient days decreased in both periods, but not significantly (p=0.058 and p=0.101, respectively). CONCLUSIONS: We found positive changes in DM-II quality trends following PCMH implementation of varying strength and onset of change, as well as duration of sustained trend.

Charge carrier formation in polythiophene/fullerene blend films studied by transient absorption spectroscopy.

We report herein a comparison of the photophysics of a series of polythiophenes with ionization potentials ranging from 4.8 to 5.6 eV as pristine films and when blended with 5 wt % 1-(3-methoxycarbonyl)propyl-1-phenyl-[6,6]C61 (PCBM). Three polymers are observed to give amorphous films, attributed to a nonplanar geometry of their backbone while the other five polymers, including poly(3-hexylthiophene), give more crystalline films. Optical excitation of the pristine films of the amorphous polymers is observed by transient absorption spectroscopy to give rise to polymer triplet formation. For the more crystalline pristine polymers, no triplet formation is observed, but rather a short-lived (approximately 100 ns), broad photoinduced absorption feature assigned to polymer polarons. For all polymers, the addition of 5 wt % PCBM resulted in 70-90% quenching of polymer photoluminescence (PL), indicative of efficient quenching of polythiophene excitons. Remarkably, despite this efficient exciton quenching, the yield of dissociated polymer+ and PCBM- polarons, assayed by the appearance of a long-lived, power-law decay phase assigned to bimolecular recombination of these polarons, was observed to vary by over 2 orders of magnitude depending upon the polymer employed. In addition to this power-law decay phase, the blend films exhibited short-lived decays assigned, for the amorphous polymers, to neutral triplet states generated by geminate recombination of bound radical pairs and, for the more crystalline polymers, to the direct observation of the geminate recombination of these bound radical pairs to ground. These observations are discussed in terms of a two-step kinetic model for charge generation in polythiophene/PCBM blend films analogous to that reported to explain the observation of exciplex-like emission in poly(p-phenylenevinylene)-based blend films. Remarkably, we find an excellent correlation between the free energy difference for charge separation (deltaG(CS)rel) and yield of the long-lived charge generation, with efficient charge generation requiring a much larger deltaG(CS)rel than that required to achieve efficient PL quenching. We suggest that this observation is consistent with a model where the excess thermal energy of the initially formed polaron pairs is necessary to overcome their Coulombic binding energy. This observation has important implications for synthetic strategies to optimize organic solar cell performance, as it implies that, at least devices based on polythiophene/PCBM blend films, a large deltaG(CS)rel (or LUMO level offset) is required to achieve efficient charge dissociation.

Regioregular poly(3-hexyl)selenophene: a low band gap organic hole transporting polymer.

The synthesis of regioregular poly(3-hexyl)selenophene is reported, and its optical and electrical properties are compared to those of regioregular poly(3-hexyl)thiophene.

Liquid-crystalline semiconducting polymers with high charge-carrier mobility.

Organic semiconductors that can be fabricated by simple processing techniques and possess excellent electrical performance, are key requirements in the progress of organic electronics. Both high semiconductor charge-carrier mobility, optimized through understanding and control of the semiconductor microstructure, and stability of the semiconductor to ambient electrochemical oxidative processes are required. We report on new semiconducting liquid-crystalline thieno[3,2-b ]thiophene polymers, the enhancement in charge-carrier mobility achieved through highly organized morphology from processing in the mesophase, and the effects of exposure to both ambient and low-humidity air on the performance of transistor devices. Relatively large crystalline domain sizes on the length scale of lithographically accessible channel lengths ( approximately 200 nm) were exhibited in thin films, thus offering the potential for fabrication of single-crystal polymer transistors. Good transistor stability under static storage and operation in a low-humidity air environment was demonstrated, with charge-carrier field-effect mobilities of 0.2-0.6 cm(2) V(-1) s(-1) achieved under nitrogen.

Radical ion pair mediated triplet formation in polymer-fullerene blend films.

Efficient triplet formation is observed for films of high ionisation potential polythiophenes blended with a fullerene derivative, and assigned to formation via geminate charge recombination of bound radical ion pair states.

Stable polythiophene semiconductors incorporating thieno[2,3-b]thiophene.

This work describes a new design methodology that allows the preparation of air stable, semiconducting thiophene polymers with high charge carrier mobilities. The incorporation of thieno[2,3-b]thiophene into a polythiophene backbone introduces cross-conjugated double bonds that disfavor full delocalization, leading to high ionization potential in comparison to a fully conjugated polythiophene, with no reduction in charge carrier mobility. The resulting solution processable polymers exhibit charge carrier mobilities up to 0.15 cm2/V s and on/off ratios greater than 105 when measured in air. Transistors exhibit lifetimes of several months in air with no encapsulation necessary.