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Nanomaterials, Nanoelectronics, and Nanofabrication Technology
Published in Michael Olorunfunmi Kolawole, Electronics, 2020
Most of the nanoelectronic devices function in this range; so, the wave behavior of the electrons has to be considered. If one continues to decrease the structural dimension, the domain of atoms and molecules is reached. If a nanoelectronic device has only one structural dimension in this range, we call it a mesoscopic device (meso means “in between”). Due to the disturbing influence of the thermal energy, quantum devices are operated at low temperatures. However, the quantum effects increase with a decrease in the feature size of the devices. Therefore, the devices must be very small if operated at room temperature. The latter is also an important point for nanoelectronics [16]. The structural smallness of the devices introduces other complexity problem; such as, the high complexity of integrated nanoelectronic systems. Modern microelectronic systems contain up to 100 million devices on a single chip. Nanoelectronics will push this number up to 1 billion devices or even more. The main problem is not only the large number of devices but also the development time and the time for testing such systems. Another important point of view is the choice of architecture for an efficient interaction between the subsystems.
Introduction to Computational Methods in Nanotechnology
Published in Sarhan M. Musa, ®, 2018
Many great advances and a large number of experimental discoveries in the field of nanoscale devices and nanotechnology call for development of new theoretical concepts, models, and computational methods not only to study the properties of available systems but also to anticipate the properties of future nanoscale materials and devices that undoubtfully will be manufactured in the incoming years. Nanoscale molecular magnets and nanoscale 2D semiconductor quantum dots exemplify the physics of nanoscale systems and some of the challenging theoretical and computational problems faced in the field. Nanostructures of this nature are of great scientific and technological interest. They also represent a tremendous computational/simulation challenge to tackle for obtaining accurate numerical results. Nanoscale size critically impacts the properties of such systems. In this transitional regime between nano/mesoscopic and bulk regimes it is very hard to predict the properties of various systems and this poses one of the obstacles to overcome. By its very nature, the study of nanoscale systems, such as molecular magnets and semiconductor quantum dots, involves multiple length and scales as well as the combination of theories and modeling approaches that have been traditionally studied separately. This means that fundamental models and computational methods that were developed in separate contexts will have to be combined and eventually new ones invented.
Low-Dimensional Semiconductors
Published in Jyoti Prasad Banerjee, Suranjana Banerjee, Physics of Semiconductors and Nanostructures, 2019
Jyoti Prasad Banerjee, Suranjana Banerjee
Low-dimensional semiconductor structures whose dimensions are intermediate between microscopic and macroscopic objects are known as mesoscopic structures. The term “mesoscopic devices” means smaller size devices having dimensions larger than microscopic object like atoms but much smaller than macroscopic object so that ohmic behavior is not exhibited by these devices. The mesoscopic systems are popularly known as nanostructures whose size may vary from a few nanometers to about 100 nm. The wave property of electrons in these mesoscopic semiconductor devices gives rise to various quantum effects.
Interaction and self-organization of inclusions in two-dimensional free-standing smectic films
Published in Liquid Crystals Reviews, 2019
P. V. Dolganov, P. Cluzeau, V. K. Dolganov
History of investigations of liquid crystals is rich with discoveries which have laid the foundation of new directions of investigations and technological applications. One of the most impressive findings that occurred in recent decades was the discovery of a new class of interactions between particles in liquid-crystalline media, which lead to self-organization of particles and to formation of structures of different type [1–3]. Self-organization occurs on scales of space and time that are convenient for human perception. Inclusions can interact on large distances significantly exceeding the particle size; as a result of self-organization, stable structures of particles are formed. In these investigations it is not only possible to observe the self-organization processes, to characterize qualitatively and quantitatively the interparticle interactions, but also to visualize the interactions which induce self-organization. Investigation of self-organization processes is of substantial interest not only for the physics of liquid crystals, but also for related scientific fields, such as, for example, creation of ordered colloidal structures, and self-organization of biological objects. As to practical applications, it is now becoming clear that mass production of new materials based on micro- and nanostructures from particles is impossible without taking into account and employing self-organization processes. Different types of inclusions can be regarded as colloidal particles in liquid-crystalline media. Special attractiveness and perspectives of research in this direction are due to ideas aimed to design new types of materials, where building blocks are not atoms or molecules but colloidal particles [4]. Different anisotropy and long-range strength of interatomic interactions and, as a consequence, the large variety of structures is related, in particular, to different structure of atomic orbitals. Their analogs can be colloidal particles, sometimes denoted ‘mesoscopic atoms’ [5] with an anisotropic interparticle interaction. Creation of materials from ‘mesoscopic atoms’ would lead to a revolutionary step not only in material science, but also in different fields of physics, chemistry, and biology. Liquid crystals are promising media for realization of structures from ‘mesoscopic atoms’. The analogs of atoms with different electron configuration in liquid crystal media are inclusions with different number and type of topological defects. Inclusions with defects are multipoles in terms of their long-range interactions with different anisotropy and strength. Employing self-organization in anisotropic liquid-crystalline media is one of the powerful and promising methods to solve these tasks.