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We report a new certified world-record efficiency for thin-film Cu(In,Ga)Se2-based photovoltaic sub-modules of 17.4%(aperture area). The record efficiency of the 16 cm2, monolithically integrated, sub-module has been independently confirmedby Fraunhofer ISE. The record device is the result of extensive co-optimization of all processing steps. Duringthe optimization process, strong focus has been put on the scalability of processes to cost-effective mass production, asreflected, for example, in Cu(In,Ga)Se2 deposition time and substrate temperature. Device manufacturing as well as resultsof electrical and material characterization is discussed.

Current available techniques for transmission electron microscopy (TEM) of tooth–biomaterial interfaces are mostly ineffective for brittle phases and impair integrated chemical and morphological characterization. Objectives The aims of this study were (1) to determine the applicability of new focused ion beam (FIB) and broad ion beam (BIB) techniques for TEM preparation of tooth–biomaterial interfaces; (2) to characterize the interfacial interaction with enamel and dentin of a conventional glass-ionomer (Chemfil Superior, DeTrey Dentsply, Germany), a 2-step self-etch (Clearfil SE, Kuraray, Japan) and a 3-step etch-and-rinse (OptiBond FL, Kerr, USA) adhesives; and (3) to characterize clinically relevant interfaces obtained from actual Class-I cavities. Methods After bonding to freshly extracted human third molars, non-demineralized and non-stained sections were obtained using the FIB/BIB techniques and examined under TEM. Results The main structures generally disclosed in conventional ultramicrotomy samples were recognized in FIB/BIB-based ones. There were not any major differences between FIB and BIB concerning the resulting ultrastructural morphology. FIB/BIB-sections enabled to clearly resolve sub-micron hydroxyapatite crystals on top of hard tissues and the interface between matrix and filler in all materials, even at nano-scale. Some investigated interfaces disclosed areas with a distinct “fog” or “melted look”, which is probably an artifact due to surface damage caused by the high-energy beam. Interfaces with enamel clearly disclosed the distinct “keyhole” shape of enamel rods sectioned at 90°, delimited by a thin electron-lucent layer of inter-rod enamel. At regions where enamel crystals ran parallel with the interface, we observed a lack of interaction and some de-bonding along with interfacial void formation. Significance The FIB/BIB methods are viable and reliable alternatives to conventional ultramicrotomy for preparation of thin sections of brittle and thus difficult to cut biomaterial–hard tissue interfaces. They disclose additional ultrastructural information about both substrates and are more suitable for advanced analytic procedures.

Since osseointegration of the respective implant is claimed by all manufacturing companies, it is obvious that not just one specific surface profile including the chemistry controls bone apposition.The purpose was to identify and separate out a particular set of surface features of the implant surfaces that can contribute as factors in the osseointegration process.The surface properties of several commercially available dental implants were extensively studied using profilometry, scanning electron microscopy, and transmission electron microscopy. Ultrathin sections prepared with focused ion beam microscopy (FIB) provided microstructural and chemical data which have not previously been communicated. The implants were the Nobel Biocare TiUnite (Nobel Biocare AB, Göteborg, Sweden), Nobel Biocare Steri-Oss HA-coated (Nobel Biocare AB, Yorba Linda, CA, USA), Astra-Tech OsseoSpeed (Astra Tech AB, Mölndal, Sweden), Straumann SLA (Straumann AG, Waldenburg, Switzerland), and the Brånemark Integration Original Fixture implant (Brånemark Integration, Göteborg, Sweden).It was found that their surface properties had differences. The surfaces were covered with crystalline TiO(2) (both anatase and rutile), amorphous titanium oxide, phosphorus doped amorphous titanium oxide, fluorine, titanium hydride, and hydroxyapatite, respectively.This indicates that the provision of osseointegration is not exclusively linked to a particular set of surface features if the implant surface character is a major factor in that process. The studied methodology provides an effective tool to also analyze the interface between implant and surrounding bone. This would be a natural next step in understanding the ultrastructure of the interface between bone and implants.

Bone-anchored titanium implants have been used for anchorage of amputation prostheses for more than one and a half decades. Histo-logical and ultrastructural analyses were performed on a forearm amputation prosthesis after being in use for more than 11 years.The implant was retrieved from the ulnar bone after a fatigue fracture of the titanium implant, and was clinically stable at the time of removal. The histological findings showed a large amount of bone within the threads and a high degree of apposition of mineralized bone to the implant surface. Ultrastructural analysis of thin samples prepared by focused ion-beam microscopy revealed an electron-dense layer at the interface and direct apposition of crystalline hydroxyapatite at the implant surface.Our observations in this retrieval study provide a structural correlate to the functional properties and clinical results of amputation prostheses.

In this paper we present results of the efficiency optimization study performed in our production line for CIGS solar modules. For three different Ga/(Ga+In) ratios two different grading settings were tested. Results indicate high impact of these parameters on efficiency, in the range of 0.5% (abs.). Increasing the Ga content in the film, results in an increase of module voltage. This is almost completely compensated by the decrease of Isc. The resulting change in efficiency is FF driven. The FF increases slightly with higher overall Ga content, but the grading plays a more important role. For the grading setting 1, which was steeper than the setting 2, the FF and consequently efficiency were significantly improved. Optimum Ga content and grading has been defined accordingly.

The aim of this work was to investigate the in vitro bioactivity of two different experimental dental luting cement formulations based on calcium aluminate (CA) in comparison with glass ionomer cement (GIC). One of the CA-based formulations was a hybrid between CA and GIC.Samples were submerged in phosphate buffered saline and stored at 37 degrees C for four periods of time: 1 h, 1 day, 7 days and 4 weeks. After storage the samples were analyzed in order to investigate if a surface layer of hydroxyapatite had formed. The analysis techniques used included grazing incidence X-ray diffraction, scanning electron microscopy, energy dispersive spectroscopy and transmission electron microscopy.Both the CA-containing formulations were found to be bioactive. The highest degree of bioactivity was found on the sample with only CA as active substance. A relatively thick and totally covering layer was already formed after 24 h. On the hybrid material hydroxyapatite was found after 7 days. The GIC showed no bioactivity during the test period.The utilization of a bioactive material for tooth restorations will give an opportunity for remineralization and a natural and durable seal of the tooth-material interface. Materials based on CA exhibit bioactivity.

NiSi1-xGex films on compressively strained as well as relaxed undoped Si1-xGex epitaxially grown substrates with x=0.06-0.30 on Si(001) wafers have been studied with respect to the relative orienta ...