Entropy-Driven Formation of Binary Semiconductor-Nanocrystal Superlattices
| Autor: | Daniel Vanmaekelbergh, Marjolein Dijkstra, Wiel H. Evers, Laura Filion, Sonja Castillo, Bart de Nijs |
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| Rok vydání: | 2010 |
| Předmět: |
Materials science
Superlattice Bioengineering Nanotechnology 02 engineering and technology 010402 general chemistry 7. Clean energy 01 natural sciences Condensed Matter::Materials Science Photovoltaics General Materials Science Phase diagram Condensed Matter::Other business.industry Mechanical Engineering General Chemistry Hard spheres Condensed Matter::Mesoscopic Systems and Quantum Hall Effect 021001 nanoscience & nanotechnology Condensed Matter Physics Thermoelectric materials 0104 chemical sciences Semiconductor Nanocrystal Chemical physics Self-assembly 0210 nano-technology business |
| Zdroj: | Nano Letters. 10:4235-4241 |
| ISSN: | 1530-6992 1530-6984 |
| DOI: | 10.1021/nl102705p |
| Popis: | One of the main reasons for the current interest in colloidal nanocrystals is their propensity to form superlattices, systems in which (different) nanocrystals are in close contact in a well-ordered three-dimensional (3D) geometry resulting in novel material properties. However, the principles underlying the formation of binary nanocrystal superlattices are not well understood. Here, we present a study of the driving forces for the formation of binary nanocrystal superlattices by comparing the formed structures with full free energy calculations. The nature (metallic or semiconducting) and the size-ratio of the two nanocrystals are varied systematically. With semiconductor nanocrystals, self-organization at high temperature leads to superlattices (AlB(2), NaZn(13), MgZn(2)) in accordance with the phase diagrams for binary hard-sphere mixtures; hence entropy increase is the dominant driving force. A slight change of the conditions results in structures that are energetically stabilized. This study provides rules for the rational design of 3D nanostructured binary semiconductors, materials with promises in thermoelectrics and photovoltaics and which cannot be reached by any other technology. |
| Databáze: | OpenAIRE |
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