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The use of graphene as transparent conducting layer in devices that require high temperature processing is proposed. The material shows stability upon thermal treatments up to 1100 °C if capped with a sacrificial silicon layer. The use of Cu foil or evaporated Cu as catalysts in Catalytic-Chemical Vapor Deposition growth gives rise to graphene of similar properties, which represents a promising result in view of its direct integration in microelectronic devices. Photovoltaic p–i–n thin film devices were fabricated on the as-deposited or annealed graphene membranes and compared with similar devices that incorporate as-deposited Indium Tin Oxide. No degradation in series resistance is observed for the annealed device. A 3.7% and 2.8% photovoltaic conversion efficiency is observed on the devices fabricated on as-transferred and on annealed graphene respectively. The major limitation derives from the high sheet resistance of the as-transferred state-of-the-art material. The results opens the way to the use of graphene in applications that require transparent conducting layers resistant to high temperature processing.

Boron doped multilayers based on silicon carbide/silicon rich carbide, aimed at the formation of silicon nanodots for photovoltaic applications, are studied. X-ray diffraction confirms the formation of crystallized Si and 3C-SiC nanodomains. Fourier Transform Infrared spectroscopy indicates the occurrence of remarkable interdiffusion between adjacent layers. However, the investigated material retains memory of the initial dopant distribution. Electrical measurements suggest the presence of an unintentional dopant impurity in the intrinsic SiC matrix. The overall volume concentration of nanodots is determined by optical simulation and is shown not to contribute to lateral conduction. Remarkable higher room temperature dark conductivity is obtained in the multilayer that includes a boron doped well, rather than boron doped barrier, indicating efficient doping in the former case. Room temperature lateral dark conductivity up to 10-3 S/cm is measured on the multilayer with boron doped barrier and well. The result compares favorably with silicon dioxide and makes SiC encouraging for application in photovoltaic devices. © 2012 Elsevier B.V. All rights reserved.

Silicon carbide/silicon rich carbide multilayers, aimed at the formation of silicon nanodots for photovoltaic applications, have been studied. The electrical properties have been investigated at the nano-scale by conductive Atomic Force Microscopy (c-AFM) and at macro-scale by temperature dependent conductivity measurements. The mixture is composed of highly conductive Si nanoclusters and moderately conductive SiC nanoclusters in a disordered matrix. The conduction mechanism takes place via band states induced by the disorder at the interface between nanodot clusters. Structural properties have been extracted by optical spectroscopy analyses. The results contribute to the understanding of the microscopical electronic mechanisms of the composite material, which is a candidate for third generation photovoltaics.

Uterus didelphys, also known as a duplicated uterus, is an embryological abnormality resulting from the failure of fusion of the Mullerian ducts, causing full uterine development to erroneously occur bilaterally. The occurrence of uterus didelphys is very low in the general population and often predisposes women to a variety of gynecological difficulties. There appears to be a high association with obstetrical complications, such as spontaneous abortion, preterm labor, cervical incompetence, and malpresentation. Uterus didelphys is also associated with urinary tract abnormalities. Presented is a case of a woman with a didelphys uterus and a twin pregnancy.

Indium tin oxide (ITO) thin films were deposited by magnetron sputtering from a ceramic target, and annealed at temperatures up to 1000 °C in N2 atmosphere. Some samples were capped in a-Si:H or spin-on glass to prevent residual oxygen contamination from the annealing ambient, and annihilation of oxygen vacancies. The electrical and optical properties were measured before and after annealing. It is found that the protecting layer effectively limits the ITO degradation up to 900 °C, whereas high transparency is preserved in all cases. The results indicate the applicability of the procedure to high temperature devices, and opens the way to the application of a variety of nanostructured materials in advanced photovoltaic devices.