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Background: Nonmissile penetrating traumatic brain injuries (pTBIs) are low-velocity injuries which can be caused by a variety of inflicting tools and represent a rare entity in children. Poor outcome has been attributed with an initial admission Glasgow Coma Scale (GCS) of Case Description: We report a case of an 11-year-old boy who presented to our ER with a GCS of 6 after being assaulted on his head by a 30 cm length metallic tent hook penetrating his forehead reaching down to the central skull base zone. Conclusion: We demonstrated that following standard recommendations in the management of pTBI which include applying the advanced trauma life support protocol in ER, acquiring the needed preoperative neuroimaging studies, avoiding moving the penetrating object till patient shifted to OR, and finally performing a planned stepwise surgical intervention through craniotomy may yield an excellent functional recovery, especially in children despite an otherwise grave initial presentation and apparently profound brain injury.

Accumulation of DNA damage in neurons is largely described in aging process and neurodegenerative diseases. Recently, RNA-binding proteins (RBPs) have emerged as important effectors of the cellular DNA damage response (DDR). The intrinsically disordered RBP FUS has been shown to play a role in multiple cellular functions, including mRNA transcription, splicing and transport, and in DDR. Besides that, FUS, together with some other RBPs, has been shown to undergo liquid-liquid phase separation (LLPS) under physiological conditions, but its precise molecular functions in DDR and the role of its LLPS remain poorly understood. The aims of this study are to: i) characterise the molecular functions of FUS in the DDR, ii) assess whether a proper repair of double strand breaks (DSB) is dependent on the LLPS of FUS. Using gene-edited HeLa cell lines, we showed that knock-out of FUS (FUS-KO) sensitised cells to genotoxic stress, impaired DSB repair, and caused changes in DDR pathways. At the molecular level, we found that FUS-KO impaired the recruitment of apical effectors of the DDR to laser-induced DNA damage sites. FUS itself is recruited within seconds to DSBs and is required for the retention of the apical DNA DSBs sensor KU. Mass spectrometry analysis revealed that FUS co-purifies with RBP implicated in DDR, including SFPQ. We demonstrate that LLPS occurs at DNA damage foci and is required for the efficient recruitment of key DDR factors. Finally, LLPS-deficient FUS variants impair the recruitment of KU and SFPQ. Overall, our findings establish for the first time that FUS-dependent LLPS contributes to the activation of the DDR and to the recruitment of DDR proteins at sites of DNA damage.

HCl gas gettering is a cheap and simple technique to reduce transition metal concentrations in silicon. It is attractive especially for low-cost silicon materials like upgraded metallurgical grade (UMG) silicon, which usually contain 3d transition metals in high concentrations. Etching of silicon by HCl gas occurs during HCl gas gettering above a certain onset temperature. The etching rate as well as the gettering efficiency was experimentally determined as a function of the gettering temperature, using UMG silicon wafers. The activation energy of the etching reaction by HCl gas was calculated from the obtained data. The gettering efficiency was determined by analyzing Ni as a representative of the 3d transition metals in the wafers with and without applied HCl gas gettering. The Ni concentrations were measured by inductively coupled plasma mass spectrometry (ICP-MS).

The perception of danger in the environment can induce physiological responses (such as a heightened state of arousal) in animals, which may cause measurable changes in the prosodic modulation of the voice (Briefer, 2012). The ability to interpret the prosodic features of animal calls as an indicator of emotional arousal may have provided the first hominins with an adaptive advantage, enabling, for instance, the recognition of a threat in the surroundings. This ability might have paved the ability to process meaningful prosodic modulations in the emerging linguistic utterances. Research has shown that humans are able to recognize different levels of arousal in mammalian calls. However, to our knowledge, no study has ever examined humans’ cross-cultural ability to identify different arousal levels in calls of species belonging to several phyologenetically distant taxa, including, for instance, mammals and birds. We addressed this issue by developing a task in which human participants of three different cultures (Canadian, German, Mandarin) listened to ten pairs of vocalizations for each of nine different vertebrate taxa. We used amplitude-controlled calls from the following species: hourglass treefrog, American alligator, black-capped chickadee, common raven, domestic pig, giant panda, African elephant, Barbary macaque, and human. Calls within each pair differed in arousal level, which was assessed based on the behavioral context of call production (Avey et al., 2011; Bowling et al., 2012; Fischer et al. 1995; Linhart et al., 2015; Reichert 2013; Stoeger et al., 2011, 2012). For each pair of vocalizations, participants were asked to identify the call with the higher level of arousal. Accuracy rate in identifying arousal in each species was higher than expected by chance in all three cultures. No significant differences were observed between cultures. This finding provides empirical support for Darwin’s hypothesis on the universality of vocal emotional communication. In order to better understand the mechanisms underlying emotional intensity recognition in our set of calls, we investigated which acoustic parameters correlate with participants’ correct responses. We performed this analysis in two steps. First, we identified two acoustic features measurable in all calls of our stimuli set: duration and a frequency related measure, the spectral center of gravity. Second, we calculated the duration and the spectral center of gravity ratio for each pair of calls and correlated these two feature comparisons with the percentage of correct responses across pairs. Our data indicate that the spectral center of gravity is the only feature found across our animal species calls, which significantly correlates with the ability to discriminate high arousal calls. Further work within this research paradigm will provide quantitative data on shared mechanisms involved in emotional vocalizations’ production and perception across animal taxa, investigating the perception of arousal in nonhuman species. This may improve our understanding of the semantic value of prosody in animal communication, and of its role in the emergence of human language. References Avey, M. T., Hoeschele, M., Moscicki, M. K., Bloomfield, L. L., & Sturdy, C. B. (2011). Neural correlates of threat perception: neural equivalence of conspecific and heterospecific mobbing calls is learned. PloS one, 6, e23844. Bowling, D. L., Sundararajan, J., Han, S. E., & Purves, D. (2012). Expression of emotion in Eastern and Western music mirrors vocalization. PLoS One, 7, e3194. Briefer, E. F. (2012). Vocal expression of emotions in mammals: mechanisms of production and evidence. Journal of Zoology, 288, 1-20. Fischer, J., Hammerschmidt, K., & Todt, D. (1995). Factors affecting acoustic variation in Barbary‐macaque (Macaca sylvanus) Disturbance Calls. Ethology, 101, 51-66. Linhart, P., Ratcliffe, V. F., Reby, D., & Špinka, M. (2015). Expression of Emotional Arousal in Two Different Piglet Call Types. PloS one, 10(8), e0135414. Reichert, M. S. (2013). Sources of variability in advertisement and aggressive calling in competitive interactions in the grey treefrog, Hyla versicolor.Bioacoustics, 22, 195-214. Stoeger, A. S., Charlton, B. D., Kratochvil, H., & Fitch, W. T. (2011). Vocal cues indicate level of arousal in infant African elephant roars. The Journal of the Acoustical Society of America, 130(3), 1700-1710. Stoeger, A. S., Baotic, A., Li, D., & Charlton, B. D. (2012). Acoustic features indicate arousal in infant giant panda vocalisations. Ethology, 118(9), 896-905.

31st European Photovoltaic Solar Energy Conference and Exhibition; 429-432, In this paper we present results about excellent p-type emitters using a rapid vapour-phase direct doping (RVD) process. The main differences between the RVD process and standard BBr3 tube furnace emitters like single sided processing, short process durations and higher degree of freedom in doping profile design are discussed in detail. Lifetime samples featuring a simple RVD emitter on one side have been processed and resulted in an emitter saturation current of less than 16 fA/cm². Solar cells with the high efficiency TOPCon structure implementing this RVD emitter have been fabricated. They show open-circuit voltages of up to 687 mV, short circuit currents of up to 41.8 mA/cm², fill factors of up to 81% and a maximum efficiency of 23.3 %.

In this work the processing sequence for an integrated interconnection concept for crystalline silicon thin-films (c-Si TF) is introduced. This concept is designed to reduce cost in the production of large-area crystalline silicon thin-film modules. Combining the advantages of classical thin-film and wafer technologies, a soldering-free interconnection of cells in the module is realized. In order to investigate the interconnection concept, a small scale laboratory process was developed and is discussed here. Mini-modules were fabricated using this processing sequence on silicon on insulator (SOI) wafers with epitaxially grown back surface field (BSF) and base layer. Despite a non-optimized metallization sequence an open circuit voltage of over 3V could be achieved for a mini-module consisting of five cells. Mini-modules were also encapsulated without loss in efficiency after encapsulation.

31st European Photovoltaic Solar Energy Conference and Exhibition; 288-291, In this publication we present free standing p- and n-type Si layers with thicknesses between 40 μm (EpiFoils) and 150 μm (EpiWafers) produced with epitaxy on electrochemically etched porous Si layers followed by mechanical lift-off. We show that reorganization and epitaxy in our quasi-inline tool leads to Si layers with very good crystal quality (etch pit density around 1000 cm-2) and low contamination levels (interstitial Fe concentration around 1010 cm-3). Thin p-type foils with just 40 μm thickness show minority carrier lifetimes of up to 80 μs mainly limited by a high dopant concentration of 5x1016 cm-3. The n-type epitaxial wafers with 150 μm thickness reach average minority carrier lifetimes of more than 1.5 ms. Appearing inhomogeneity of minority carrier lifetimes over the sample area are found to be due to surface cleaning process but not bulk quality related issues. The excellent lifetimes together with the very constant dopant concentration of our Si layers is sufficient for high efficiency solar cell architectures and a conversion efficiency of 20 % can be exceeded [1].

29th European Photovoltaic Solar Energy Conference and Exhibition; 1673-1677, This paper presents a summary of the EU project “roll to module processed crystalline silicon thinfilms” (R2M-Si). The aim of this project was to lift off c-Si-thin-films in a cost effective manner, and to process them to integrated interconnected solar cells. One major goal was therefore to provide Si foil material for solar cells with a high efficiency potential. Within the R2M-Si project both the theoretical understanding and the actual process development of porosifying and detaching layers from flat wafers as well as from the circumference of a silicon rod have been investigated. Studies on crystal orientation dependence of the porosification along with tool development towards a continuous formation of a separation layer were accompanied by in depth understanding and thus optimization of the reorganization and subsequent epitaxial growth process. Finally the introduction of a special attachment process and an integrated solar cell concept could be achieved.

Reducing the module prices by increasing the efficiency of solar cells is one of the major challenges in today’s photovoltaic research. The emitter formation by epitaxial growth offers a cost-efficient and faster alternative to the standard furnace diffusion process. The efficiency potential of epitaxial emitters > 22% has already been proven using a single wafer, low pressure, chemical vapour deposition tool. The purpose of this work is to show the potential of epitaxially grown emitters by APCVD (atmospheric pressure chemical vapour deposition) compared to diffused emitters. The APCVD formation of epitaxial emitters at 1,050 °C can be realised as high throughput inline process and only takes 1-2 min, whereas the diffusion process using POCl3 takes up to 60 min. Simulations show an increase in voltage of DVOC = +10 mV and a reduction in saturation current J0 of 30% for the epitaxial emitter. The lifetime experiments of solar cells with epitaxial emitter exhibit a diffusion length Leff > 750 µm and an emitter saturation current of J0e < 50 fA/cm² on a planar 10 Wcm p-type FZ wafer. Another important aim of this work is to evaluate the limitations of epitaxial emitters due to high thermal budget, interface recombination and the change of reflective properties on textured wafers due to the deposition process. Solar cell efficiencies up to 18.4% on p-type and 20.0% on n-type wafers presented in this paper underline that the emitter epitaxy by APCVD is a competitive process for the emitter formation.

29th European Photovoltaic Solar Energy Conference and Exhibition; 747-752, Cost reduction is still a major goal in photovoltaic development. Silicon foils offer the possibility to reduce silicon consumption and with this production costs while maintaining a high efficiency potential. In this work silicon foils are fabricated by implementation of a release layer in a silicon substrate, reorganization of this layer and epitaxial thickening prior to detachment. For the formation of the release layer two approaches are investigated, hydrogen implantation and electrochemical etching of porous silicon. Hydrogen implanted layers reorganize during heat treatment to layers with low amounts of small pores or with blisters depending on the implantation dose. The overall amount of pores can be increased by applying several implantation processes. With the more often applied electrochemically etched porous silicon as release layer the defect density in the foil deposited in a lab-type CVD reactor could be reduced to (6 ± 2) x 103 cm-2 by optimization of the reorganization process. Effective carrier lifetimes up to 56 μs are measured. Additionally, 5 x 5 cm2 foils deposited in a continuous CVD reactor are presented.

The effective minority carrier lifetimes on epitaxial silicon thin-film material have been measured successfully using two independent microwave-detected photoconductivity decay setups. Both measurement setups are found to be equally suited to determine the minority carrier lifetime of crystalline silicon thin-film (cSiTF) material. The different measurement conditions to which the sample under investigation is exposed are critically analyzed by both simulations and measurements on a large number of lifetime samples. No systematic deviation between the lifetime results from different measurement setups could be observed, underlining the accuracy of the determined lifetime value. Subsequently, a method to separate the epitaxial bulk lifetime and the total recombination velocity, consisting of front surface and interface recombination between the epitaxial layer and the substrate, is presented. The method, based on different thicknesses of the epitaxial layer, is applied to all batches of this investigation. Each batch consists of samples with the same material quality but different epitaxial layer thicknesses whereas different batches differ in their material quality. In addition, the same method is also successfully applied on individual cSiTF samples. From the results, it can be concluded that the limiting factor of the effective minority carrier lifetime for the investigated solar-grade cSiTF material is the elevated recombination velocity at the interface between epitaxial layer and the substrate compared with microelectronic-grade material. In contrast, the samples cannot be classified into different material qualities by their epitaxial bulk lifetimes. Even on multicrystalline substrate, solar-grade material can exhibit high epitaxial bulk lifetimes comparable to microelectronic-grade material.

28th European Photovoltaic Solar Energy Conference and Exhibition; 2657-2661, Silicon CVD is required to realise the upcoming “kerfless” c-Si thin-film solar cell concepts, like EpiCell, Lift-off and recrystallized wafer equivalent solar cells. To realise these solar cell concepts, a high throughput reactor with the possibility of continuous deposition is needed. For this reason, the ConCVD is the first epitaxy tool with a continuous wafer transport through the entire system. The requirements for such a machine are very sophisticated. Despite the open construction, the flammable and toxic reactor atmosphere must be separated from the surrounding atmosphere and the other way around, impurities must not get inside the reactor. This work reports on process improvement and solar cell results on layers deposited in the ConCVD at Fraunhofer ISE. The ConCVD (Continuous CVD) is a link between lab type reactors and a production reactor (ProConCVD), also developed at the Fraunhofer ISE. Setup improvements could enhance deposition conditions by providing a particle free environment. Furthermore, processes optimisations in this new setup lead to a solar cell result of 13.8%.

28th European Photovoltaic Solar Energy Conference and Exhibition; 2630-2633, In this work the realization of a concept for integrated interconnected crystalline silicon thin film solar cells in a laboratory process is described. This module concept, referred to as IntegRex (Integrated interconnection of recrystallized silicon layers), is developed for recrystallized or lift-off crystalline silicon layers. Following the classical thin film approach the crystalline silicon thin film is divided into individual cell strips and interconnected monolithically on a substrate. To investigate the individual processing steps silicon on insulator (SOI) wafers with a buried oxide layer and epitaxially deposited back surface field (BSF) and base are used instead of recrystallized or lift-off crystalline silicon films. A first batch of IntegRex mini-modules on SOI wafers was processed. Despite a not yet optimized metallization scheme, a VOC of over 3 V could be reached for a mini-module consisting of five cells. Problems that occurred in the metallization process are presented here and a possible solution is discussed.

28th European Photovoltaic Solar Energy Conference and Exhibition; 827-830, Reducing the total costs of modules by increasing the efficiency of solar cells is one of the major challenges in today’s photovoltaic research. The emitter epitaxy by atmospheric pressure chemical vapour deposition (APCVD) offers a cost-efficient and faster alternative to the standard furnace diffusion process. The epitaxial emitter formation at 1050 °C only takes 1-2 min whereas the diffusion process using POCl3 takes up to 60 min. The purpose of this work is to show the potential of epitaxial grown emitters compared to diffused emitters. PC1D simulations show an increase in voltage of VOC = + 10 mV and a reduction in saturation current J0e of 30% for the epitaxial emitter. These advantages are due to lower surface recombination velocity and reduction of Auger recombination of the optimised emitter profile. The lifetime experiments including an epitaxial emitter show a diffusion length Leff of 750 μm and an emitter saturation current of J0e = 46 fA/cm² on a planar 10 cm p-type FZ wafer. Another important aim of this work is to determine the limitations of epitaxial emitters due to thermal degradation of the base material, interface recombination and the change of reflective properties on textured wafers due the deposition process. In a first batch, solar cell efficiencies up to 18.4 % underline that emitter epitaxy by APCVD is a competitive process for the emitter formation.

28th European Photovoltaic Solar Energy Conference and Exhibition; 2662-2665, Low-cost high-throughput epitaxy is one of the keystones for reducing the PV module cost to far below 50 €ct/Wp by new “kerfless” cell concepts. At Fraunhofer ISE the ProConCVD (Production Continuous Chemical Vapour Deposition) was developed to demonstrate feasibility of such a process. First long term experiments could proof the reliability and the reproducibility of the tool. 1300 multicrystaline silicon (mc-Si) wafers of 156 mm x 156 mm size were coated during 24 experiments in 4 weeks. With SiCl4 as a precursor it was possible to deposit 9 μm thick epitaxial layers within 45 minutes. Thickness homogeneity higher than 90% was achieved over nearly 270 mm deposition width. Since at the edges of the reaction chamber a reduction of the deposited Si film can be observed, we investigated in Computational Fluid Dynamic (CFD) to identify the underlying reasons. The purpose of this work is to report the potential and the limitations of the current models. It could be shown that the gas inlet setup of the ProConCVD already uses 80 % of its theoretical potential in reference to the growth rate and the layer thickness homogeneity in transport direction is higher than 87 %.

27th European Photovoltaic Solar Energy Conference and Exhibition; 2453-2458, A concept for integrated interconnected crystalline silicon thin film solar cells is presented. Following the classical thin film approach the crystalline silicon thin film is divided into individual cell stripes and interconnected monolithically, directly on the substrate. Taking advantage of the crystalline quality of the material, the interconnection is realized using screen printing pastes. In this paper we focus our experimental investigations on the separation of cell stripes and the interconnection via screen printing. The cell separation is either done by oxide masking and KOH etching or by laser ablation and a subsequent etch step. For the interconnection not only metallization pastes are required, but also an isolating material to protect the edge of the cell against shunting. Different isolating screen printing pastes were tested for their isolation properties against metallization pastes. In further experiments the influence of different firing parameters was investigated. The cell stripe width strongly affects the series resistance of the module, since it is a single side contacted concept where only the back surface field (BSF) is responsible for the electrical conductivity on the rear. Therefore the series resistance is estimated in dependence on the cell stripe width.