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AFM of QDs

I. Self-Assembled Semiconductor Epitaxical Quantum Nanostructures for Electronics / Optoelectronics

     Self-assembled epitaxical quantum nanostructures are a class of nanostructures created by exploiting naturally occurring forces between the constituents, usually atoms and/or molecules, and a crystalline substrate such that the atoms of the resulting nanostructure have a definite spatial relationship with the underlying substrate atoms. Since the nanostructures form during a film growth process, rather than through post-growth patterning and etching on the nanoscale, these have been dubbed self-assembled (or self-organized) nanostructures. Examples of such nanostructures are seen in the images shown here.

     To learn more about how these are created, their physical properties, and their use in advanced semiconductor devices, click on the appropriate sections below.

I.1 Nanostructure Synthesis and Structural Evolution:

     Emphasis is on atomic level understanding and controlled manipulation of the synthesis processes, control on quantum dot size distribution, and spatially-selective positioning of countable ensembles of QDs. If you can't make it, you can't study it!

I.2 Electronic Properties:

     Mostly absorption/luminescence and photoconduction related.

I.3 Devices:

     Emphasis is on demonstration of concepts via existence theorems. Current focus is mainly on mid (2-5 µm) and long wavelength (8-12 µm) quantum dot infra-red photodetectors (QDIPs).

     The QD detector program is being carried out in collaboration with Prof. J.C.Campbell (Univ. of Virginia; EE Dept.).

     A major part of this effort is supported by the MURI (Multidisciplinary University Research Initiative) Program on Nanoscience through the AFOSR.

Other research areas

II.Nanocrystal Quantum Dots      
III.Hybrid Biochemical / Inorganic Structures

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TEM of Vertical Self Orgnization
PhotoCurrent of 5layers of 2ML QDs
Hign Detectivity of QDIP