Virtual Synthesis of Sub-Nanoscale Materials With Prescribed Physical Properties
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L11.40.1
Virtual Synthesis of Sub-Nanoscale Materials With Prescribed Physical Properties Liudmila A. Pozhar1, Alan T. Yeates1, Frank Szmulowicz2 and William C. Mitchel3 1
Air Force Research Laboratory, Materials and Manufacturing Directorate, Polymer Materials Branch (AFRL/MLBP), 2941 Hobson Way, Wright-Patterson Air Force Base, OH 45433, U.S.A. 2 University of Dayton, University of Dayton Research Institute, 300 College Park, Dayton, OH 45469, U.S.A. 3 Air Force Research Laboratory, Materials and Manufacturing Directorate, Sensor Materials Branch (AFRL/MLPS), 3005 Hobson Way, Wright-Patterson Air Force Base, OH 45433, U.S.A.
ABSTRACT Properties of electronic energy spectra of several small virtual clusters (known as small quantum dots, or QDs) composed of In, Ga and As atoms are investigated for the further use in nanoheterostructure (NHS) units of pre-designed electronic properties. Modern quantum statistical physics methods relate these properties to electronic transport properties of such systems and therefore, lead to realization of a virtual (i.e., fundamental theory- based, computational) approach to synthesis of sub-nanoscale electronic materials with pre-designed electronic properties [1].
INTRODUCTION Recent progress in experimental fabrication and materials characterization techniques led to development of advanced nanomaterials (such as single semiconductor QDs of Ga, In, As, Si, C, Ge, and other atoms, atrifical molecules, NHSs, etc.) with effective characteristic size from tens to hundreds of nanometers. Further progress toward higher density of elements and miniaturization of integrated circuits and devices is limited by insufficient information on electronic and thermodynamic properties of small finite atomic systems. At present, nanomaterials for the use in opto-electronics are fabricated experimentally according to existing experimental experience, because the corresponding theoretical foundations are primarily relevant to macroscopically large systems. This makes such fabrication difficult, unreliable and expensive business with largely unpredictable results. In contrast, virtual approach [1] to materials synthesis relies on first-principle, self-consistent theoretical and computational methods that relate the key properties of the synthesized materials and (i) the processing parameters, (ii) the processed system structure and composition, and (iii) the emerging material structure, chemistry, composition and physical properties. While, due to the hardware and software restrictions, this approach is not yet entirely feasible in the case of larger systems, such as large QDs and the corresponding NHSs, it is feasible for small atomic clusters, such as QDs composed of several tenths of atoms that can be experimentally realized, for example, in confinement (such as that provided by pores of nanoporous membranes and similar carriers). Therefore, in the case of such small systems one can use and develop further existing general, fundamental theoretical methods in conjunction with computations and si
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