Metallic bonding - 123seminarsonly.com · Metallic bonding size‐dependency on the optical...
Transcript of Metallic bonding - 123seminarsonly.com · Metallic bonding size‐dependency on the optical...
![Page 1: Metallic bonding - 123seminarsonly.com · Metallic bonding size‐dependency on the optical properties The size‐dependency on the optical properties of CdSe nanocrystals. With decreasing](https://reader035.fdocuments.net/reader035/viewer/2022063012/5fc86f171658f7795e64efdd/html5/thumbnails/1.jpg)
11/28/2011
1
Metallic bonding
![Page 2: Metallic bonding - 123seminarsonly.com · Metallic bonding size‐dependency on the optical properties The size‐dependency on the optical properties of CdSe nanocrystals. With decreasing](https://reader035.fdocuments.net/reader035/viewer/2022063012/5fc86f171658f7795e64efdd/html5/thumbnails/2.jpg)
11/28/2011
2
Metallic bonding
size‐dependency on the optical properties
The size‐dependency on the optical properties of CdSe nanocrystals. With decreasing size, the fluorescence peak is shifted to shorter wavelengths
![Page 3: Metallic bonding - 123seminarsonly.com · Metallic bonding size‐dependency on the optical properties The size‐dependency on the optical properties of CdSe nanocrystals. With decreasing](https://reader035.fdocuments.net/reader035/viewer/2022063012/5fc86f171658f7795e64efdd/html5/thumbnails/3.jpg)
11/28/2011
3
Au
Ag
Specific heat
color
Properties vary with size
melting point
Bandgap
conductivity
![Page 4: Metallic bonding - 123seminarsonly.com · Metallic bonding size‐dependency on the optical properties The size‐dependency on the optical properties of CdSe nanocrystals. With decreasing](https://reader035.fdocuments.net/reader035/viewer/2022063012/5fc86f171658f7795e64efdd/html5/thumbnails/4.jpg)
11/28/2011
4
Density of states (DOS) for electrons in bulk semiconductors (3‐D, blue), quantum wells(2‐D, red), quantum wires (1‐D, green), and quantum dots (0‐D, black).( , ), q ( , g ), q ( , )
Repeat 24 times
Nanoscale = High Ratio of Surface Area to Vol.Nanoscale = High Ratio of Surface Area to Vol.
For example, 5 cubic centimeters For example, 5 cubic centimeters –– about 1.7 cm per side about 1.7 cm per side –– of of material divided 24 times will produce 1 nanometer cubes and material divided 24 times will produce 1 nanometer cubes and spread in a single layer could cover a football fieldspread in a single layer could cover a football field
Source: Clayton Teague, NNI
![Page 5: Metallic bonding - 123seminarsonly.com · Metallic bonding size‐dependency on the optical properties The size‐dependency on the optical properties of CdSe nanocrystals. With decreasing](https://reader035.fdocuments.net/reader035/viewer/2022063012/5fc86f171658f7795e64efdd/html5/thumbnails/5.jpg)
11/28/2011
5
![Page 6: Metallic bonding - 123seminarsonly.com · Metallic bonding size‐dependency on the optical properties The size‐dependency on the optical properties of CdSe nanocrystals. With decreasing](https://reader035.fdocuments.net/reader035/viewer/2022063012/5fc86f171658f7795e64efdd/html5/thumbnails/6.jpg)
11/28/2011
6
![Page 7: Metallic bonding - 123seminarsonly.com · Metallic bonding size‐dependency on the optical properties The size‐dependency on the optical properties of CdSe nanocrystals. With decreasing](https://reader035.fdocuments.net/reader035/viewer/2022063012/5fc86f171658f7795e64efdd/html5/thumbnails/7.jpg)
11/28/2011
7
MBE setup
![Page 8: Metallic bonding - 123seminarsonly.com · Metallic bonding size‐dependency on the optical properties The size‐dependency on the optical properties of CdSe nanocrystals. With decreasing](https://reader035.fdocuments.net/reader035/viewer/2022063012/5fc86f171658f7795e64efdd/html5/thumbnails/8.jpg)
11/28/2011
8
Physical vapour depositin
a) Electron beam evaporationb) Ion Plating Processc) Sputtering
torus‐shaped argon plasma
![Page 9: Metallic bonding - 123seminarsonly.com · Metallic bonding size‐dependency on the optical properties The size‐dependency on the optical properties of CdSe nanocrystals. With decreasing](https://reader035.fdocuments.net/reader035/viewer/2022063012/5fc86f171658f7795e64efdd/html5/thumbnails/9.jpg)
11/28/2011
9
![Page 10: Metallic bonding - 123seminarsonly.com · Metallic bonding size‐dependency on the optical properties The size‐dependency on the optical properties of CdSe nanocrystals. With decreasing](https://reader035.fdocuments.net/reader035/viewer/2022063012/5fc86f171658f7795e64efdd/html5/thumbnails/10.jpg)
11/28/2011
10
Layer by Layer deposition
Self organize on a substrate surface
Functionalization of NPs
![Page 11: Metallic bonding - 123seminarsonly.com · Metallic bonding size‐dependency on the optical properties The size‐dependency on the optical properties of CdSe nanocrystals. With decreasing](https://reader035.fdocuments.net/reader035/viewer/2022063012/5fc86f171658f7795e64efdd/html5/thumbnails/11.jpg)
11/28/2011
11
Carbon nanotubes
metallic
Semimetallicor semiconductor
Vertically aligned CNTs
![Page 12: Metallic bonding - 123seminarsonly.com · Metallic bonding size‐dependency on the optical properties The size‐dependency on the optical properties of CdSe nanocrystals. With decreasing](https://reader035.fdocuments.net/reader035/viewer/2022063012/5fc86f171658f7795e64efdd/html5/thumbnails/12.jpg)
11/28/2011
12
Functionalization of CNTs
Functionalization of CNTs
![Page 13: Metallic bonding - 123seminarsonly.com · Metallic bonding size‐dependency on the optical properties The size‐dependency on the optical properties of CdSe nanocrystals. With decreasing](https://reader035.fdocuments.net/reader035/viewer/2022063012/5fc86f171658f7795e64efdd/html5/thumbnails/13.jpg)
11/28/2011
13
Functionalization of CNTs
Fullerene
![Page 14: Metallic bonding - 123seminarsonly.com · Metallic bonding size‐dependency on the optical properties The size‐dependency on the optical properties of CdSe nanocrystals. With decreasing](https://reader035.fdocuments.net/reader035/viewer/2022063012/5fc86f171658f7795e64efdd/html5/thumbnails/14.jpg)
11/28/2011
14
Functionalization of Fullerene
SEM of TiO2
![Page 15: Metallic bonding - 123seminarsonly.com · Metallic bonding size‐dependency on the optical properties The size‐dependency on the optical properties of CdSe nanocrystals. With decreasing](https://reader035.fdocuments.net/reader035/viewer/2022063012/5fc86f171658f7795e64efdd/html5/thumbnails/15.jpg)
11/28/2011
15
TEM of TiO2
TEM of TiO2
![Page 16: Metallic bonding - 123seminarsonly.com · Metallic bonding size‐dependency on the optical properties The size‐dependency on the optical properties of CdSe nanocrystals. With decreasing](https://reader035.fdocuments.net/reader035/viewer/2022063012/5fc86f171658f7795e64efdd/html5/thumbnails/16.jpg)
11/28/2011
16
TEM of CuO
TEM of CuO