In situ thickness control of black phosphorus field-effect transistors via ozone treatment

A simple and reproducible method to control the thickness of black phosphorus flakes in real time using a UV/ozone treatment is demonstrated. Back-gated black phosphorus field-effect transistors (FETs) were fabricated using thick black phosphorus flakes obtained by thinning of black phosphorus, as oxygen radicals generated by UV irradiation formed phosphorus oxides on the surface. In order to monitor the thickness effect on the electrical properties, the fabricated FETs were loaded in the UV/ozone chamber, where both the optical (micro-Raman spectroscopy and optical microscopy) and electrical properties (current-voltage characteristics) were monitored in situ. We observed an intensity decrease of the Raman modes of black phosphorus while the field-effect mobility and on/off ratio increased by 48% and 6,800%, respectively. The instability in ambient air limits the investigation and implementation of ultra-thin black phosphorus. However, the method reported in this study allowed us to start with thick black phosphorous flakes, providing a reliable approach for optimizing the electrical performance of black phosphorus-based electronic devices. We believe that these results can motivate further studies using mono- and few-layer black phosphorus.N

Degradation of Black Phosphorus upon Environmental Exposure and Encapsulation Strategies to Prevent It

Along this chapter we discuss about one of the main issues in black phosphorus research: Its environmental instability. We will discuss the works were the role of the environmental exposure has been studied and the reported works describing strategies to effectively encapsulate black phosphorus to preserve its pristine properties

Guidelines on myocardial revascularization

Guidelines and Expert Consensus Documents summarize and evaluate all available evidence with the aim of assisting physicians in selecting the best management strategy for an individual patient suffering from a given condition, taking into account the impact on outcome and the risk benefit ratio of diagnostic or therapeutic means. Guidelines are no substitutes for textbooks and their legal implications have been discussed previously. Guidelines and recommendations should help physicians to make decisions in their daily practice. However, the ultimate judgement regarding the care of an individual patient must be made by his/her responsible physician(s). The recommendations for formulating and issuing ESC Guidelines and Expert Consensus Documents can be found on the ESC website (http://www.escardio.org/knowledge/ guidelines/rules). Members of this Task Force were selected by the European Society of Cardiology (ESC) and the European Association for Cardio-Thoracic Surgery (EACTS) to represent all physicians involved with the medical and surgical care of patients with coronary artery disease (CAD). A critical evaluation of diagnostic and therapeutic procedures is performed including assessment of the risk benefit ratio. Estimates of expected health outcomes for society are included, where data exist. The level of evidence and the strength of recommendation of particular treatment options are weighed and graded according to predefined scales, as outlined in Tables 1 and 2. The members of the Task Force have provided disclosure statements of all relationships that might be perceived as real or potential sources of conflicts of interest. These disclosure forms are kept on file at European Heart House, headquarters of the ESC. Any changes in conflict of interest that arose during the writing period were notified to the ESC. The Task Force report received its entire financial support from the ESC and EACTS, without any involvement of the pharmaceutical, device, or surgical industry. ESC and EACTS Committees for Practice Guidelines are responsible for the endorsement process of these joint Guidelines. The finalized document has been approved by all the experts involved in the Task Force, and was submitted to outside specialists selected by both societies for review. The document is revised, and finally approved by ESC and EACTS and subsequently published simultaneously in the European Heart Journal and the European Journal of Cardio-Thoracic Surgery. After publication, dissemination of the Guidelines is of paramount importance. Pocket-sized versions and personal digital assistant-downloadable versions are useful at the point of care. Some surveys have shown that the intended users are sometimes unaware of the existence of guidelines, or simply do not translate them into practice. Thus, implementation programmes are needed because it has been shown that the outcome of disease may be favourably influenced by the thorough application of clinical recommendations