Simultaneous Contacting and Interconnection of Passivated Emitter and Rear Solar Cells

The back end process of passivated emitter and rear cells (PERC) consists of at least one laser process and three screen-printing steps followed by the stringing and tabbing of the cells. To reduce the number of steps we have developed a process that metallizes the rear side including contact formation and simultaneously interconnects the cells. We attach an Al foil to an encapsulant layer. By laser processing we form 'laser-fired and bonding contacts' (LFBC) on the passivated rear side of the solar cells. The Al foil contacting the rear is laser welded to the Ag screen-printed front side metallization of the next cell and thus forms the cell interconnection. The laser contacts on the rear show a surface recombination velocity Scont for the contact regions of cm/s and a contact resistivity of 3.52 m?cm2. We present a first proof-of concept module combining the in-laminate Ag-Al laser welding and the LFBC reaching an efficiency of 18.4%. In accelerated aging test modules show no degradation (< 1% in efficiency) after 100 humidity-free cycles.Federal Ministry for Environment, Nature Conservation, and Nuclear Safety/FKZ/0325192State of Lower Saxon

Relationship between Beliefs of Teachers about and Their Use of Explicit Instruction When Fostering Students’ Scientific Inquiry Competencies

An efficient approach to fostering students’ scientific inquiry (SI) competencies (e.g., planning investigations) is to combine student engagement in inquiry activities with explicit instruction that addresses corresponding concepts (e.g., the control-of-variables strategy). Despite its effectiveness, explicit instruction on SI-related concepts seems to be rarely employed in science classrooms. As a vital component of professional competence, teachers’ beliefs are a potential cause for the rare use of explicit instruction. The aim of this study is to investigate the relationship between teachers’ beliefs about the usefulness of explicit instruction as well as their own abilities and teacher performance. In a mixed method approach, the beliefs of N = 16 teachers were captured with a questionnaire, while their teaching practice was approximated through a combination of a lesson planning task and a semi-structured interview. Analyses of response patterns, a qualitative content analysis of the planned lessons, and correlation analyses were used to investigate the relationship between beliefs and performance. The findings suggest that beliefs about the usefulness of explicit instruction for fostering SI competencies may be a necessary but not a sufficient condition for its implementation. Furthermore, the results suggest the importance of assessing and investigating teachers’ beliefs on a goal-specific level

Überzeugungen von Lehrkräften zum Lehren und Lernen von Fachinhalten und Fachmethoden und deren Beziehung zu unterrichtsnahem Handeln

Der Aufbau fachinhaltlicher und fachmethodischer Kompetenzen ist ein zentrales Ziel naturwissenschaftlicher Bildung. Ein effektiver Ansatz zur Förderung dieser Kompetenzen ist die explizite Thematisierung zugehöriger Kenntnisse. Im Unterricht scheinen aber vor allem fachinhaltliche und nur selten fachmethodische Kenntnisse explizit thematisiert zu werden. Ausgehend von der Annahme, dass dieser Unterschied u.a. durch die Überzeugungen von Lehrkräften bedingt ist, wurden mit einem Fragebogen die Überzeugungen zum Lehren und Lernen von Fachinhalten und Fachmethoden von N = 175 Lehrkräften erfasst. Zusätzlich wurde eine Teilstichprobe von n = 16 Lehrkräften im Rahmen von Interviews u. a. zum Planen einer Stunde zum Aufbau fachmethodischer Kompetenzen aufgefordert und die Umsetzung expliziter Thematisierung inhaltsanalytisch untersucht. Die Ergebnisse zeigen graduelle Unterschiede in den zielspezifischen Überzeugungen von Lehrkräften. So sind diese z.B. häufig der Überzeugung, dass das explizite Thematisieren von Kenntnissen zwar für beide Ziele wirksam ist, aber für das Lehren und Lernen von Fachinhalten nützlicher als für das von Fachmethoden. Diese Überzeugungen werden nur z.T. konsistent umgesetzt, da die explizite Thematisierung fachmethodischer Kenntnisse kaum wesentlicher Bestandteil der geplanten Stunden ist. So scheinen die Überzeugungen zur Bedeutsamkeit expliziter Thematisierung eine notwendige, aber keine hinreichende Bedingung für deren Umsetzung zu sein. Insgesamt legen die Befunde nahe, dass es wichtig ist, die Überzeugungen von Lehrkräften zielspezifisch zu untersuchen

Relationship between Beliefs of Teachers about and Their Use of Explicit Instruction When Fostering Students’ Scientific Inquiry Competencies

An efficient approach to fostering students’ scientific inquiry (SI) competencies (e.g., planning investigations) is to combine student engagement in inquiry activities with explicit instruction that addresses corresponding concepts (e.g., the control-of-variables strategy). Despite its effectiveness, explicit instruction on SI-related concepts seems to be rarely employed in science classrooms. As a vital component of professional competence, teachers’ beliefs are a potential cause for the rare use of explicit instruction. The aim of this study is to investigate the relationship between teachers’ beliefs about the usefulness of explicit instruction as well as their own abilities and teacher performance. In a mixed method approach, the beliefs of N = 16 teachers were captured with a questionnaire, while their teaching practice was approximated through a combination of a lesson planning task and a semi-structured interview. Analyses of response patterns, a qualitative content analysis of the planned lessons, and correlation analyses were used to investigate the relationship between beliefs and performance. The findings suggest that beliefs about the usefulness of explicit instruction for fostering SI competencies may be a necessary but not a sufficient condition for its implementation. Furthermore, the results suggest the importance of assessing and investigating teachers’ beliefs on a goal-specific level

The NutriAct Family Study: a web-based prospective study on the epidemiological, psychological and sociological basis of food choice

BACKGROUND: Most studies on food choice have been focussing on the individual level but familial aspects may also play an important role. This paper reports of a novel study that will focus on the familial aspects of the formation of food choice among men and women aged 50–70 years by recruiting spouses and siblings (NutriAct Family Study; NFS). METHODS: Data is collected prospectively via repeatedly applied web-based questionnaires over the next years. The recruitment for the NFS started in October 2016. Participants are recruited based on an index person who is actively participating in the European Prospective Investigation into Cancer and Nutrition (EPIC)-Potsdam study. This index person was asked to invite the spouse, a sibling or an in-law. If a set of family members agreed to participate, access to individualized web-based questionnaires assessing dietary intake, other health related lifestyle habits, eating behaviour, food responsiveness, personality, self-regulation, socio-economic status and socio-cultural values was provided. In the first phase of the NSF, recruitment rates were monitored in detail and participants’ comments were analysed in order to improve the feasibility of procedures and instruments. DISCUSSION: Until August 4th 2017, 4783 EPIC-Participants were contacted by mail of which 446 persons recruited 2 to 5 family members (including themselves) resulting in 1032 participants, of whom 82% had started answering or already completed the questionnaires. Of the 4337 remaining EPIC-participants who had been contacted, 1040 (24%) did not respond at all, and 3297 (76%) responded but declined, in 51% of the cases because of the request to recruit at least 2 family members in the respective age range. The developed recruitment procedures and web-based methods of data collection are capable to generate the required study population including the data on individual and inter-personal determinants which will be linkable to food choice. The information on familial links among the study participants will show the role of familial traits in midlife for the adoption of food choices supporting healthy aging