The Intrinsic Route to Pro-Environmental Behaviour

Engaging in pro-environmental behaviours is oftentimes associated with some personal costs. Despite this, many people do engage in different types of pro-environmental behaviours. Why is this the case? In this dissertation, we propose that people engage in pro-environmental behaviours because they are intrinsically motivated to do so. Across four empirical chapters, we, indeed, found a strong and consistent relationship between intrinsic motivation and different pro-environmental behaviours. Importantly, we found that intrinsic motivation remains an important factor encouraging pro-environmental behaviour, even after controlling for the perceived personal costs associated with the behaviour. Furthermore, intrinsic motivation is not weakened in the presence of a financial incentive, and it can be strengthened by frequent environmental information provision to further promote pro-environmental behaviour change

Probing the charge generation and recombination in thin-film, optoelectronic devices

Sustainably and environment-friendly manufactured semiconductors are at-tractive candidates for next generation electronic and optoelectronic appli-cations ranging from memory storage and computation, to power manage-ment and energy generation. In this regard, organic semiconductors, i.e., semiconductors based on conjugated carbon-based molecules and polymers derived from earth abundant elements, are the subject of intense basic re-search and technological development efforts. Understanding the funda-mental processes governing these low-mobility and disordered semiconduct-ing materials is therefore key to establish next generation applications based upon flexible and solution-processible organic semiconductors as global com-mercial technologies.The work presented in this thesis focuses on the investigation of charge generation and recombination processes on thin film optoelectronic devices based upon organic semiconductors. A suite of experimental techniques, im-proved measurement setups, and expanded approaches are presented, and form the basis of comprehensive studies on state-of-the-art, high-efficiency organic photovoltaic systems. Specifically, an external quantum efficiency measurement technique with unprecedented dynamic range will be detailed. Using this enhanced apparatus, an approach allowing one to accurately de-termine charge generation quantum yields is introduced. After this, an extended technique to probe photogenerated charge carrier densities is out-lined and applied to thin-film solar cells. Having emphasized the importance of studying charge generation, a combined theoretical and experimental ex-ploration of the light intensity dependence of photocurrent and charge col-lection efficiency under the influence of various loss mechanisms is described. These insights provide the basis of a comprehensive study on organic so-lar cells, where recombination caused by localized trap states is found to be universally present under operational conditions limiting photocurrent and power-conversion efficiency. Overall, the work presented in this thesis expands on existing techniques and approaches, and yields important new understanding as to the device physics of thin-film, optoelectronic applica-tions

Transformational fieldwork, or, How might a sustainable cultural provision in the rural/small town context be framed?

While a lot has been written in the past two decades about the impact of participatory arts on people in urban places, my practice-based research aims to fill the gap in relation to the rural context - often places with little traditional arts provision. Based on the development of Deveron Projects in Huntly/Aberdeenshire - where the "town is the venue", rather than a gallery or arts centre - my aim is to show how cultural provision can be framed through a combination of durational commitment to place and effective cultural management. To do this, I have been reflecting on twenty-five years of working in the small-town community setting, examining retrospectively my role as curator/producer. Underpinned by Scottish philosopher Patrick Geddes's Place/Work/Folk thinking machine and artist Joseph Beuys' idea of social sculpture, as well as other thinkers' engagement with place and social context, I show how we can create a cultural ecology that assists the wellbeing of rural communities. The research is based on four case studies that explain how the collaboration with artists can lead to transformative change through participatory, practice-led projects. Through them, my inquiry leads from the identification of socio-political themes to collaborative development of the projects between community, artists and ourselves - the "Anthro-Producers". The research shows why and how art provision in rural locations can be structured sustainably through field-research akin to anthropological methods. The ensuing approach I call Transformational Fieldwork, a form of cultural management that combines social engagement with research methods relating to long-term participatory observation. Structured around 16 inter-woven administrative/artistic principles, this framework offers a toolkit for continued arts development in the rural community context. My contribution to curatorial sustainability discourse is, therefore, to show step-by-step how Transformational Fieldwork can contribute to rural development and community wellbeing in places that, unlike urban cultural contexts, have limited involvement with contemporary art

Understanding the Role of Order in Y‐Series Non‐Fullerene Solar Cells to Realize High Open‐Circuit Voltages

Non-fullerene acceptors (NFAs) as used in state-of-the-art organic solar cells feature highly crystalline layers that go along with low energetic disorder. Here, the crucial role of energetic disorder in blends of the donor polymer PM6 with two Y-series NFAs, Y6, and N4 is studied. By performing temperature-dependent charge transport and recombination studies, a consistent picture of the shape of the density of state distributions for free charges in the two blends is developed, allowing an analytical description of the dependence of the open-circuit voltage VOC on temperature and illumination intensity. Disorder is found to influence the value of the VOC at room temperature, but also its progression with temperature. Here, the PM6:Y6 blend benefits substantially from its narrower state distributions. The analysis also shows that the energy of the equilibrated free charge population is well below the energy of the NFA singlet excitons for both blends and possibly below the energy of the populated charge transfer manifold, indicating a down-hill driving force for free charge formation. It is concluded that energetic disorder of charge-separated states has to be considered in the analysis of the photovoltaic properties, even for the more ordered PM6:Y6 blend

Electron-donating amine-interlayer induced n-type doping of polymer:nonfullerene blends for efficient narrowband near-infrared photo-detection

Inherently narrowband near-infrared organic photodetectors are highly desired for many applications, including biological imaging and surveillance. However, they suffer from a low photon-to-charge conversion efficiencies and utilize spectral narrowing techniques which strongly rely on the used material or on a nano-photonic device architecture. Here, we demonstrate a general and facile approach towards wavelength-selective near-infrared phtotodetection through intentionally n-doping 500–600 nm-thick nonfullerene blends. We show that an electron-donating amine-interlayer can induce n-doping, resulting in a localized electric field near the anode and selective collection of photo-generated carriers in this region. As only weakly absorbed photons reach this region, the devices have a narrowband response at wavelengths close to the absorption onset of the blends with a high spectral rejection ratio. These spectrally selective photodetectors exhibit zero-bias external quantum efficiencies of ~20–30% at wavelengths of 900–1100 nm, with a full-width-at-half-maximum of ≤50 nm, as well as detectivities of >1012 Jones

Understanding Performance Limiting Interfacial Recombination in pin Perovskite Solar Cells

Perovskite semiconductors are an attractive option to overcome the limitations of established silicon based photovoltaic (PV) technologies due to their exceptional opto‐electronic properties and their successful integration into multijunction cells. However, the performance of single‐ and multijunction cells is largely limited by significant nonradiative recombination at the perovskite/organic electron transport layer junctions. In this work, the cause of interfacial recombination at the perovskite/C60 interface is revealed via a combination of photoluminescence, photoelectron spectroscopy, and first‐principle numerical simulations. It is found that the most significant contribution to the total C60‐induced recombination loss occurs within the first monolayer of C60, rather than in the bulk of C60 or at the perovskite surface. The experiments show that the C60 molecules act as deep trap states when in direct contact with the perovskite. It is further demonstrated that by reducing the surface coverage of C60, the radiative efficiency of the bare perovskite layer can be retained. The findings of this work pave the way toward overcoming one of the most critical remaining performance losses in perovskite solar cells

Understanding complex biomolecular systems through the synergy of molecular dynamics simulations, NMR spectroscopy and X-Ray crystallography

Proteins and DNA are essential to life as we know it and understanding their function is understanding their structure and dynamics. The importance of the latter is being appreciated more in recent years and has led to the development of novel interdisciplinary techniques and approaches to studying protein function. Three techniques to study protein structure and dynamics have been used and combined in different ways in the context of this thesis and have led to a better understanding of the three systems described herein. X-ray crystallography is the oldest and still arguably most popular technique to study macromolecular structures. Nuclear magnetic resonance (NMR) spectroscopy is a not much younger technique that is a powerful tool not only to probe molecular structure but also dynamics. The last technique described herein are molecular dynamics (MD) simulations, which are only just growing out of their infancy. MD simulations are computer simulations of macromolecules based on structures solved by X-ray crystallography or NMR spectroscopy, that can give mechanistic insight into dynamic processes of macromolecules whose amplitudes can be estimated by the former two techniques. MD simulations of the model protein GB3 (B3 immunoglobulin-binding domain of streptococcal protein G) were conducted to identify origins of discrepancies between order parameters derived from different sets of MD simulations and NMR relaxation experiments.The results highlight the importance of time scales as well as sampling when comparing MD simulations to NMR experiments. Discrepancies are seen for unstructured regions like loops and termini and often correspond to nanosecond time scale transitions between conformational substates that are either over- or undersampled in simulation. Sampling biases can be somewhat remedied by running longer (microsecond time scale) simulations. However, some discrepancies persist over even very long trajectories. We show that these discrepancies can be due to the choice of the starting structure and more specifically even differences in protonation procedures. A test for convergence on the nanosecond time scale is shown to be able to correct for many of the observed discrepancies. Next, MD simulations were used to predict in vitro thermostability of members of the bacterial Ribonuclease HI (RNase H) family of endonucleases. Thermodynamic stability is a central requirement for protein function and a goal of protein engineering is improvement of stability, particularly for applications in biotechnology. The temperature dependence of the generalized order parameter, S, for four RNase H homologs, from psychrotrophic, mesophilic and thermophilic organisms, is highly correlated with experimentally determined melting temperatures and with calculated free energies of folding at the midpoint temperature of the simulations. This study provides an approach for in silico mutational screens to improve thermostability of biologically and industrially relevant enzymes. Lastly, we used a combination of X-ray crystallography, NMR spectroscopy and MD simulations to study specificity of the interaction between Drosophila Hox proteins and their DNA target sites. Hox proteins are transcription factors specifying segment identity during embryogenesis of bilaterian animals. The DNA binding homeodomains have been shown to confer specificity to the different Hox paralogs, while being very similar in sequence and structure. Our results underline earlier findings about the importance of the N-terminal arm and linker region of Hox homeodomains, the cofactor Exd, as well as DNA shape, for specificity. A comparison of predicted DNA shapes based on sequence alone with the shapes observed for different DNA target sequences in four crystal structures when in complex with the Drosophila Hox protein AbdB and the cofactor Exd, shows that a combined ”induced fit”/”conformational selection” mechanism is the most likely mechanism by which Hox homeodomains recognize DNA shape and achieve specificity. The minor groove widths for all sequences is close to identical for all ternary complexes found in the different crystal structures, whereas predicted shapes vary between the different DNA sequences. The sequences that have shown higher affinity to AbdB in vitro have a predicted DNA shape that matches the observed DNA shape in the ternary complexes more closely than the sequences that show low in vitro affinity to AbdB. This strongly suggests that the AbdB-Exd complex selects DNA sequences with a higher propensity to adopt the final shape in their unbound form, leading to higher affinity. An additional AbdB monomer binding site with a strongly preformed binding competent shape is observed for one of the oligomers in the reverse complement strand of one of the canonical (weak) Hox-Exd complex binding site. The shape preference seems strong enough for AbdB monomer binding to compete with AbdB-Exd dimer binding to that same oligomer, suggested by the presence of both binding modes in the same crystal. The monomer binding site is essentially able to compete with the dimer binding site, even though binding with the cofactor is not possible, because its shape is very close to the ideal shape. A comparison of different crystal structures solved herein and in the literature as well as a set of molecular dynamics simulations was performed and led to insights about the importance of residues in the Hox N-terminal arm for the preference of certain Hox paralogs to certain DNA shapes. Taken together all these insights contribute to our understanding of Hox specificity in particular as well as protein-DNA interactions in general

Glanz in der Bibliothek Hartmannsdorf: Neu- und Umgestaltung lockt Leser an

Die Industriegemeinde Hartmannsdorf mit ihren rund 4.600 Einwohnern liegt nahe der Stadt Chemnitz. Bereits seit 1938 besteht in Hartmannsdorf eine Bibliothek. Nach mehreren Umzügen innerhalb des Gemeindegebietes hat die Bibliothek seit nunmehr knapp neun Jahren einen festen Standort. Im selben Objekt sind zugleich der Kinderhort, der Heimatverein beziehungsweise die Ortsgruppe des Deutschen Roten Kreuzes untergebracht. In unmittelbarer Nähe befinden sich zudem die Grundschule und die in freier Trägerschaft befindliche Mittelschule. Durch diese Einrichtungen sind beste Voraussetzungen für die Nutzung der Bibliothek durch Kinder und Jugendliche geschaffen. Aber auch zahlreiche Senioren und Erwachsene gehören zu den insgesamt mehr als 300 registrierten aktiven Lesern

The effects of a financial incentive on motives and intentions to commute to work with public transport in the short and long term

The present research aimed to evaluate the effectiveness of a three-week free public transport card in encouraging people to commute to work using public transport both in the short term (while the incentive is in place) and long term (after the incentive is removed). Moreover, we tested effects of the free public transport card on motivations to use public transport. Findings from our longitudinal field study showed that participants had strong intentions to use public transport while the incentive was in place, but intentions to commute to work using public transport decreased in the long-term, suggesting that the incentive was effective while in place, but not when it was removed. Moreover, participants rated the financial motives to commute to work using public transport as less important after the incentive was removed, suggesting that financial incentives provide people with a temporary motive to engage in the desired behaviour, which may explain the short-term effectiveness of the incentive. We did not observe that the free public transport card crowded out participants’ intrinsic motivation to travel by public transport. Theoretical and practical implications are discussed

Determining Ultralow Absorption Coefficients of Organic Semiconductors from the Sub‐Bandgap Photovoltaic External Quantum Efficiency

Energy states below the bandgap of a semiconductor, such as trap states or charge transfer states in organic donor acceptor blends, can contribute to light absorption. Due to their low number density or ultrasmall absorption cross-section, the absorption coefficient of these states is challenging to measure using conventional transmission reflection spectrophotometry. As an alternative, the external quantum efficiency (EQE) of photovoltaic devices is often used as a representative of the absorption coefficient, where the spectral line shape of the EQE is considered to follow the absorption coefficient of the active layer material. In this work, it is shown that the subbandgap EQE is subject to thickness dependent low finesse cavity interference effects within the device, making this assumption questionable. A better estimate for the absorption coefficient is obtained when EQE spectra corresponding to different active layer thicknesses are fitted simultaneously for one attenuation coefficient using an iterative transfer matrix method. The principle is demonstrated for two model acceptor-donor systems (PCE12ITIC and PBTTTPC71BM) and accurate subgap absorption coefficients are determined. This approach has particular relevance for both understanding sub-gap states and their utilization in organic optoelectronic devices