rabbithong 2007-08-15 22:48
A. P. Alivisatos教授S&N文章汇编
最新的利用Lattice-mismatch strains形成纳米棒超晶的文章,制备复合纳米材料的又一新思路.
看来我们还是的好好学习一下物理才能够在材料领域有所作为!
[b][size=5]Spontaneous Superlattice Formation in Nanorods Through Partial Cation Exchange[/size][/b]
Lattice-mismatch strains are widely known to control nanoscale pattern formation in heteroepitaxy, but
such effects have not been exploited in colloidal nanocrystal growth. We demonstrate a colloidal route
to synthesizing CdS-Ag2S nanorod superlattices through partial cation exchange. Strain induces the
spontaneous formation of periodic structures. Ab initio calculations of the interfacial energy and
modeling of strain energies show that these forces drive the self-organization of the superlattices. The
nanorod superlattices exhibit high stability against ripening and phase mixing. These materials are
tunable near-infrared emitters with potential applications as nanometer-scale optoelectronic devices.
:downloads :link :box
**** Hidden Message *****
rabbithong 2007-08-15 22:57
关于太阳能电池的文章
Science 2005, 310, 462-465
[size=5]Air-Stable All-Inorganic Nanocrystal Solar Cells Processed from Solution[/size]
Ilan Gur,1,3 Neil A. Fromer,1 Michael L. Geier,3
A. Paul Alivisatos1,2*
We introduce an ultrathin donor-acceptor solar cell composed entirely of
inorganic nanocrystals spin-cast from solution. These devices are stable in air,
and post-fabrication processing allows for power conversion efficiencies
approaching 3% in initial tests. This demonstration elucidates a class of
photovoltaic devices with potential for stable, low-cost power generation.
:downloads :box
**** Hidden Message *****
rabbithong 2007-08-16 12:01
[size=6]Cation Exchange Reactions in Ionic Nanocrystals[/size]
Dong Hee Son,1 Steven M. Hughes,2 Yadong Yin,1
A. Paul Alivisatos1,2*
Cation exchange has been investigated in a wide range of nanocrystals of
varying composition, size, and shape. Complete and fully reversible exchange
occurs, and the rates of the reactions are much faster than in bulk cation
exchange processes. A critical size has been identified below which the shapes
of complex nanocrystals evolve toward the equilibrium shape with lowest
energy during the exchange reaction. Above the critical size, the anion
sublattice remains intact and the basic shapes of the initial nanocrystals are
retained throughout the cation exchange. The size-dependent shape change
can also be used to infer features of the microscopic mechanism.
**** Hidden Message *****
rabbithong 2007-08-16 12:07
Kirkendall Effect在材料制备中的应用
Kirkendall Effect原来是指两种扩散速率不同的金属在扩散过程中会形成缺陷，
Alivisatos利用纳米尺度的Kirkendall Effect在硫化钴的纳米颗粒，该文章发表在2003年的Science杂志上，从此利用此效应制备中空纳米颗粒成为研究的热点
[size=6]Formation of Hollow Nanocrystals Through the Nanoscale Kirkendall Effect[/size]
Yadong Yin, Robert M. Rioux, Can K. Erdonmez, Steven Hughes,
Gabor A. Somorjai, A. PaulAl ivisatos*
Hollow nanocrystals can be synthesized through a mechanism analogous to the
Kirkendall Effect, in which pores form because of the difference in diffusion rates
between two components in a diffusion couple. Starting with cobalt nanocrystals,
we show that their reaction in solution with oxygen and either sulfur
or selenium leads to the formation of hollow nanocrystals of the resulting oxide
and chalcogenides. This process provides a general route to the synthesis of
hollow nanostructures of a large number of compounds. A simple extension of
the process yielded platinum–cobalt oxide yolk-shell nanostructures, which
may serve as nanoscale reactors in catalytic applications.
**** Hidden Message *****
rabbithong 2007-08-16 14:55
[b]对金纳米粒子进行精确组装(具有确定的粒子数和粒子间距)[/b]
Nature 382, 609 - 611 (15 August 1996); doi:10.1038/382609a0
[size=6]Organization of 'nanocrystal molecules' using DNA[/size]
A. Paul Alivisatos*, Kai P. Johnsson†, Xiaogang Peng*, Troy E. Wilson†, Colin J. Loweth†, Marcel P. Bruchez Jr* & Peter G. Schultz†
* Department of Chemistry, University of California at Berkeley, Berkeley, California 94720, USA and Molecular Design Institute, Lawrence Berkeley National Laboratory, Berkeley, California 94701, USA.
† Howard Hughes Medical Institute, Department of Chemistry, University of California at Berkeley, Berkeley, California 94720, USA.
PATTERNING matter on the nanometre scale is an important objective of current materials chemistry and physics. It is driven by both the need to further miniaturize electronic components and the fact that at the nanometre scale, materials properties are strongly size-dependent and thus can be tuned sensitively1. In nanoscale crystals, quantum size effects and the large number of surface atoms influence the, chemical, electronic, magnetic and optical behaviour2—4. 'Top-down' (for example, lithographic) methods for nanoscale manipulation reach only to the upper end of the nanometre regime5; but whereas 'bottom-up' wet chemical techniques allow for the preparation of mono-disperse, defect-free crystallites just 1–10 nm in size6–10, ways to control the structure of nanocrystal assemblies are scarce. Here we describe a strategy for the synthesis of'nanocrystal molecules', in which discrete numbers of gold nanocrystals are organized into spatially defined structures based on Watson-Crick base-pairing interactions. We attach single-stranded DNA oligonucleotides of defined length and sequence to individual nanocrystals, and these assemble into dimers and trimers on addition of a complementary single-stranded DNA template. We anticipate that this approach should allow the construction of more complex two-and three-dimensional assemblies.
References 1. Alivisatos, A. P. Science 271, 933−937 (1996). | ISI | ChemPort |
2. Bawendi, M. G., Steigerwald, M. L. & Brus, L. E. Annu. Rev. Phys. Chem 41, 477−496 (1990). | ISI | ChemPort |
3. Weller, H. Angew. Chem. Int. Edn. Engl. 32, 41−53 (1993).
4. Tolbert, S. H. & Alivisatos, A. P. Annu. Rev. Phys. Chem. 46, 595−625 (1995). | Article | ChemPort |
5. Waugh, F. R. et al. Phys. Rev. Lett. 75, 705−708 (1995). | Article | PubMed | ChemPort |
6. Murray, C. B., Norris, D. J. & Bawendi, M. G. J. Am. Chem. Soc. 115, 8706−8715 (1993). | Article | ISI | ChemPort |
7. Littau, K. A., Szajowski, P. J., Muller, A. J., Kortan, A. R. & Brus, L. E. J. Phys. Chem. 97, 1224−1230 (1993). | Article | ISI | ChemPort |
8. Guzelian, A. A. et al. J. Phys. Chem. 100, 7212−7219 (1996). | Article | ISI | ChemPort |
9. Schmid, G. Chem. Rev. 92, 1709−1727 (1992). | Article | ISI | ChemPort |
10. Haneda, K. Can. J. Phys. 65, 1233−1241 (1987). | ChemPort |
11. Spanhel, L., Weller, H. & Henglein, A. J. Am. Chem. Soc. 109, 6632−6635 (1987). | Article | ChemPort |
12. Gopidas, K. R., Bohorquez, M. & Kamat, P. V. J. Phys. Chem. 94, 6435−6440 (1990). | Article | ChemPort |
13. Brust, M., Bethell, D., Schiffrin, D. J. & Kiely, C. J. Adv. Mater. 7, 795−797 (1995). | Article | ISI | ChemPort |
14. Lawless, D., Kapoor, S. & Meisel, D. J. Phys. Chem. 99, 10329−10335 (1995). | Article | ChemPort |
15. Pag. X. et al. Angew. Chem. (submitted).
16. Peschel, S. & Schmid, G. Angew. Chem. Int. Edn. Engl. 34, 1442−1443 (1995). | ChemPort |
17. Whetten, R. L. et al. Adv. Mater. 8, 428−433 (1996). | Article | ISI | ChemPort |
18. Andres, R. P. et al. Science 272, 1323−1325 (1996). | PubMed | ISI | ChemPort |
19. Klein, D. L., McEuen, P. L., Bowen-Katari, J. E., Roth, R., Alivisatos, A. P. Appl. Phys. Lett. 68, 2574−2576 (1996). | Article | ISI | ChemPort |
20. Covin, V. L., Goldstein, A. N., Alivisatos, A. P. J. Am. Chem. Soc. 114, 5221−5230 (1992). | Article | ISI | ChemPort |
21. Fendler, J. H., Meldrum, F. C. Adv. Mater. 7, 607−632 (1995). | Article | ChemPort |
22. Peng, X. et al. J. Phys. Chem. 96, 3412−3416 (1992). | Article | ChemPort |
23. Murray, C. B., Kagan, C. R. & Bawendi, M. G. Science 270, 1335−1338 (1995). | ISI | ChemPort |
24. Vossmeyer, T. et al. Science 267, 1476−1479 (1995). | ISI | ChemPort |
25. Herron, N., Calabrese, J. C., Farneth, W. E. & Wang, Y. Science 259, 1426−1428 (1993). | ChemPort |
26. Bentzon, M. D., van Wonterghem, J., Morup, S., Tholen, A. & Koch, C. J. W. Phil. Mag. B 60, 169−178 (1989). | ISI | ChemPort |
27. Seeman, N. C. Mater. Res. Soc. Symp. Proc. 292, 123−135 (1993). | ChemPort |
28. Niemeyer, C. M., Sano, T., Smith, C. L. & Cantor, C. R. Nucleic. Acids Res. 22, 5530−5539 (1994). | PubMed | ISI | ChemPort |
29. Zuckermann, R. N., Corey, D. R. & Schultz, P. G. Nucleic. Acids Res. 15, 5305−5321 (1987). | PubMed | ChemPort |
30. Maniatis, T., Frisch, E. F. & Sambrook, J. Molecular Cloning: A Laboratory Manual (Cold Spring Harbor Lab., Cold Spring Harbor, NY, 1989).
**** Hidden Message *****
rabbithong 2007-08-17 15:14
[size=5]Colloidal nanocrystal heterostructures with linear and branched topology[/size]
Delia J. Milliron1,2, Steven M. Hughes1,2, Yi Cui1,2, Liberato Manna1,2*,
Jingbo Li3, Lin-Wang Wang3 & A. Paul Alivisatos1,2
1Department of Chemistry, University of California, 2Materials Science Division,
and 3Computational Research Division, Lawrence Berkeley National Laboratory,
Berkeley, California, 94720, USA
* Present address: National Nanotechnology Lab of INFM, Via Arnesano, 73100 Lecce Lecce, Italy
The development of colloidal quantum dots has led to practical applications of quantum confinement, such as in solutionprocessed solar cells1, lasers2 and as biological labels3. Further scientific and technological advances should be achievable if these colloidal quantum systems could be electronically coupled in a general way. For example, this was the case when it became possible to couple solid-state embedded quantum dots into quantum dot molecules4,5. Similarly, the preparation of nanowires with linear alternating compositions—another form of coupled quantum dots—has led to the rapid development of single-nanowire light-emitting diodes6 and single-electron transistors7. Current strategies to connect colloidal quantum dots use organic coupling agents8,9, which suffer from limited control over coupling parameters and over the geometry and complexity of assemblies. Here we demonstrate a general approach for fabricating inorganically coupled colloidal quantum dots and rods, connected epitaxially at branched and linear junctions within single nanocrystals. We achieve control over branching and composition throughout the growth of nanocrystal heterostructures to independently tune the properties of each component and the nature of their interactions. Distinct dots and rods are coupled through potential barriers of tuneable height and width, and arranged in three-dimensional space at well-defined angles and distances. Such control allows investigation of potential applications ranging from quantum information processing to artificial photosynthesis.
不知道怎么加图,我直接粘贴不可以.
**** Hidden Message *****
[[i] 本帖最后由 rabbithong 于 2007-08-17 16:33 编辑 [/i]]
rabbithong 2007-08-17 15:25
上篇文章的基础工作也是发表在Nature上面的,值得提出的时期第一作者是中国人xianggang peng,现在是University of Arkansas的教授了,也是纳米材料制备方面的大牛(将会发贴与大家分享).
[size=5]Shape control of CdSe nanocrystals[/size]
Xiaogang Peng*, Liberato Manna, Weidong Yang, Juanita Wickham, Erik Scher, Andreas Kadavanich & A. P. Alivisatos
Department of Chemistry, University of California at Berkeley, and Lawrence
Berkeley National Laboratory, Berkeley, California 94720, USA
Nanometre-size inorganic dots, tubes and wires exhibit a wide range of electrical and optical properties that depend sensitively on both size and shape, and are of both fundamental and technological interest. In contrast to the syntheses of zero-dimensional systems, existing preparations of one-dimensional systems often yield networks of tubes or rods which are difficult to separate. And, in the case of optically active II±VI and III±V semiconductors, the resulting rod diameters are too large to exhibit quantum confinement effects. Thus, except for some metal nanocrystals, there are no methods of preparation that yield soluble and monodisperse particles that are quantum-confined in two of their dimensions. For semiconductors, a benchmark preparation is the growth of nearly spherical II±VI and III± V nanocrystals by injection of precursor molecules into a hot surfactant. Here we demonstrate that control of the growth kinetics of the II±VI semiconductor cadmium selenide can be used to vary the shapes of the resulting particles from a nearly spherical morphology to a rod-like one, with aspect ratios as large as ten to one. This method should be useful, not only for testing theories of quantum confinement, but also for obtaining particles with spectroscopic properties that could prove advantageous in biological labelling experiments and as chromophores in lightemitting diodes.
**** Hidden Message *****
[[i] 本帖最后由 rabbithong 于 2007-08-17 16:34 编辑 [/i]]