Characterization and processing of semiconductor nanostructures and application as devices

Abstract

This project has as its main goal, to implement and consolidate common efforts and the leadership between a numbers of researchers working in a key scientific and technological area, corroborating their common expertises. The main objective is to strength the preexisting collaboration between experimentalists and theoreticians through studies of related phenomena link to interface effects, confinement produced during epitaxial growth of semiconductor nanostructures: Heterostructures, quantum dots and rings, and different nanowire structures. These effects respond to and/or modulate the optical, transport, mechanical, magnetic and piezoelectric properties of these systems and, thus, form the basis for their applications as optoelectronic and spintronic devices. From their knowledge and control may result strategic elements that support the evolution of technological perspectives of design, synthesis, processing (doping, lithography, electric contacts, etc) and application of these nanostructures. This proposal is based on five inter-related and complementary pillars: (i) The design, growth and processing samples of nanostructured systems having optical windows and electric contacts; (ii) Their structural characterizations; (iii) Experimental characterization of optical, magnetic and transport properties; (iv) theoretical simulations, via molecular dynamics, of structural and dynamical properties (v) Simulation of optical and transport effects associated to classical elements provided from molecular dynamic results. The practical problems evidenced by the new research tendencies on the confined and extended states show the interesting basic questions to be studied, understood and, possibly, explored. Effects of different nature are present and their theoretical treatments, as well as refined experimental techniques attach to different areas of the Physics and require different methodologies to treat them. The themes of research in this proposal are focused, always as possible, to obtain original results in these new and highly strategic research lines. Certainly, they will allow introducing scientific initiation, undergraduate and graduate students to th fundamental experimental and theoretical tools that are important for development studies and projects in a broad area related to Condensed Matter Physics. In the present project we intend to proceed and give a deeper insight to the several research lines looking for characterization of electronic and spin properties of confined and extended states in semiconductor systems and, thus, to strength the different channels of important collaboration, between experimental as well as theoretical groups established in different national and international centers of research The general and broad themes composing this proposal, involving complementary theoretical and experimental techniques or approaches, may be grouped along the lines: 1. To control of spin properties, using electronic structure engineering of OD, 1D and 2D states in coupled systems where tunneling processes may be manipulates by different external field configurations. To understand the effects detect in the optical emissions (photoluminescence) and associated to spin dynamic of carriers in these semiconductor heterostructures. 2. To elucidate the role of strain-stress and the modulation of transport of carriers (electrons and holes) through quantum wires and other one-dimensional heretostructured systems. 3. To study effects of structural properties in quantum wire systems and one-dimensional chain of dots and the modification and modulation of their optical response and carrier mobilities. 4. To study and explore the spin-orbit effects on the properties of nanostructured systems. Study effects of hybridization of spin states on the anisotropy and on the modulation of the optical response. 5. Look for comprehension and characterization of nanomagnetism and anomalous diamagnetism. (AU)