Preface: Phys. Status Solidi C 6/2012

Abstract

AbstractThis proceedings issue is a selective collection of papers presented at Symposium B “Amorphous Nanostructured Materials” which was conducted during the E‐MRS Fall Meeting 2011, Warsaw, Poland. The symposium program covered various aspects of amorphous materials science and technology, including the preparation of materials and structures, the characterization and study of their properties (structural, optical, electrical, magnetic), the performance of devices. The objective of the symposium was to put together leading scientists working in the field and to update the research achievements in the area.Among the most substantial issues, discussions at the symposium highlighted the importance of structures and materials that combine amorphous and crystalline phases or that allow phase transitions between such phases. These structures have new physical properties and open the way to new potential applications in the fields of information and energy, in particular for information storage, light emission, and solar cells. Great emphasis was put on silicon‐based materials and structures, either from low temperature (amorphous, polymorphous, microcrystalline silicon) or high temperature processes (silicon nanoparticles and nanocrystals). Recent progress has been achieved in understanding the doping and defect properties of amorphous silicon, as well as the behavior of heterostructures comprising thin amorphous silicon films. Light emission properties of silicon nanoclusters and silicon‐based materials like rare‐earth implanted amorphous silicon dioxide and silicon oxicarbide layers were also underlined. A carrier multiplication effect in silicon nanocrystals embedded in an amorphous silicon oxide matrix was reported, implying the relaxation of photogenerated hot carriers not only at photon absorption sites but also through energy transfer into neighboring nanocrystals with creation of additional electron–hole pairs. Utilization of this effect should improve the efficiency of silicon‐based solar cells. Future trends in materials physics include the study of silicon–germanium nanocrystals and the use for hybrid silicon–organic electronics. In particular, silicon nanocrystals could be used in conjunction with organic semiconductors for hybrid bulk heterojunction solar cells. Studies of other nanostructured silicon‐based devices such as silicon heterojunction and silicon nanowires solar cells were also presented.Considerable attention was paid to the fabrication and properties of metallic nanostructures. In particular, a new method was reported allowing production of amorphous metal nanoparticles that, contrary to their crystalline counterparts, do not coagulate when approaching each other. This unusual property permitted fabrication of thin films consisting of closely packed but still individual nanoparticles. When made of magnetic materials, the characteristics of such films were shown to be determined by magnetic exchange interaction between the particles combined with particle self‐organization. As a result, the blocking temperature of the films was found to be close to room temperature, which is a property being important in magnetic storage application.Related to the above‐mentioned subjects, the issue content is organized as follows. First four articles are devoted to different aspects of light emission from silicon‐based materials (silicon oxicarbide, silicon and metal oxide clusters). The second group of three articles deals with correlation between structure and electrical properties of the materials based on amorphous silicon. Next, four articles consider technology and structure formation mechanisms of amorphous silicon. The following three articles touch upon the problem of silicon‐based solar cells. The last group of four articles deals with fabrication and properties of promising amorphous chalcogenides, metals, metal oxides, and carbon materials.All contributing authors are greatly acknowledged for their input to this issue.The symposium was sponsored by INCATTECH LLC (the company is located in St. Petersburg, Russia, www.incattech.com).