[ODCAD] Nano conveyor of Metal
Source: Chemical Eng. News, May 3, 2004
Scientists from Univ. of Californian, Berkeley and Lawrence Berkeley National Lab have found a way to transport molten metal along nanotube.
Physics professor Alex Zettl, postdoc Christ Regan and their coworkers applied electrical current to a multiwalled carbon nanotube (MWNT), and the heat generated can melt contacting metal crystal. The metal then migrate along the tube from the anode to the cathode. The metal particles are shuttled along the surface of the nano tube in atomic form without evaporation. They observed that the metal can move over a greater distance than 2 um.
Potentially, this may be useful technology to make nano circuit or nano device combining metal with nano tube.
Copy right owned by OD Software Incorporated (ODSI)(http://www.odcad.com/)-the expert and toolkit provider of electronic material, device
Tuesday, April 27, 2004
[ODCAD] C6 Nanotube, Why is it so attractive to Electronic Device Industry?
First of all, I would like ask you the question: Is C6 nanotube organic material ?
The answer is "Yes, it is". C6 nanotube is same as graphite in terms of chemical bond. Each carbon
uses sp2 atomic orbit to form sigma bond with next atom. The extra p
orbit can form pi bond that is why the material can be conductive.
When we talk about C6 nanotube, we should realize that we are talking
about a set of compound (not single specific material). The structure
of a specific C6 nanotube is determined by the way rolling graphite
sheet into a tube. Therfore, the fundamental electroniv properties
(such as energy gap Eg) are then determined by the structure. The
nanotube can be semiconductor to conductor. The optical properties
have a wide range too.
The best conduction of nanotube is even better than gold Au (~10
times). Its charge carrier mobility is extremly high.
The strength of nanotube is better than any fiber you can make.
The density of nanotube is much lighter than any metal.
With so many special properties, what reason you can give to deny the
interest from the electronic device industry?
ODCAD from OD Software Incorporated (ODSI) (http://www.odcad.com/)-the expert and toolkit provider of electronic material, device.
First of all, I would like ask you the question: Is C6 nanotube organic material ?
The answer is "Yes, it is". C6 nanotube is same as graphite in terms of chemical bond. Each carbon
uses sp2 atomic orbit to form sigma bond with next atom. The extra p
orbit can form pi bond that is why the material can be conductive.
When we talk about C6 nanotube, we should realize that we are talking
about a set of compound (not single specific material). The structure
of a specific C6 nanotube is determined by the way rolling graphite
sheet into a tube. Therfore, the fundamental electroniv properties
(such as energy gap Eg) are then determined by the structure. The
nanotube can be semiconductor to conductor. The optical properties
have a wide range too.
The best conduction of nanotube is even better than gold Au (~10
times). Its charge carrier mobility is extremly high.
The strength of nanotube is better than any fiber you can make.
The density of nanotube is much lighter than any metal.
With so many special properties, what reason you can give to deny the
interest from the electronic device industry?
ODCAD from OD Software Incorporated (ODSI) (http://www.odcad.com/)-the expert and toolkit provider of electronic material, device.
Tuesday, April 20, 2004
[ODCAD] Nanofabrication :Imprint Technology of Organic Material
Conventional lithography technology limits its scaling capability by the wave length of light used. The nanotechnology requires line size 100nm or less. The UV light is being pushed to its limit for the task.
One approach is to use short wave length light such as x ray to replace current UV light. This may allow quality small size device production. However, this type of light usually is not time efficient because it can not penetrate very deep of the material resulting a long time production.
However, if it is just making a mold with short wave length light, it is fine because the mold can be reused many times in wafer process for small size device.
A mold can be made from a hard material, and not easily wearable. A desirable pattern can be made with short wave length light. After it is made, it can be used as a stamp.
Organic material such as polymer is usually soft. It can be stamped by a mold. In this way, a desired pattern can be made. This is imprinting technology. It is simple, cheap, and fast. Currently, HP uses this technology in high density organic memory fabrication. The pitch is in the range 40 nm (could be less).
Copy right owned by OD Software Incorporated (ODSI)-the expert and tool kit provider of electronic material, device
Conventional lithography technology limits its scaling capability by the wave length of light used. The nanotechnology requires line size 100nm or less. The UV light is being pushed to its limit for the task.
One approach is to use short wave length light such as x ray to replace current UV light. This may allow quality small size device production. However, this type of light usually is not time efficient because it can not penetrate very deep of the material resulting a long time production.
However, if it is just making a mold with short wave length light, it is fine because the mold can be reused many times in wafer process for small size device.
A mold can be made from a hard material, and not easily wearable. A desirable pattern can be made with short wave length light. After it is made, it can be used as a stamp.
Organic material such as polymer is usually soft. It can be stamped by a mold. In this way, a desired pattern can be made. This is imprinting technology. It is simple, cheap, and fast. Currently, HP uses this technology in high density organic memory fabrication. The pitch is in the range 40 nm (could be less).
Copy right owned by OD Software Incorporated (ODSI)-the expert and tool kit provider of electronic material, device
[ODCAD] OLED Color tuned by External Voltage
Achieving multi color OLED device is a challenge task. One approach is to use multi layered structure. The simple one is a five layer structure which are Cathode, Red emissive layer, Green emissive layer, Blue emissive layer, and Anode layer.
One important fact to be used is that the charge carrier mobility is field effect. Usually, higher field, larger mobility. This is more effective for electron as charge carrier in organic semiconductor. Charge carrier mobility decides where hole from anode combines with the electron from the cathode in OLED device along the direction of field. This charge recombination may result in emitting light. Making use of the fact of the mobility effected by field, One can control charge recombination region by adjusting the field strength (voltage applied). As an example, a Red layer is close to the cathode layer. Applying relatively low voltage can result in lower electron mobility compared with hole. This leads to charge recombine at Red layer resulting in Red emitting light. In the same way, one can achieve different color by applying proper voltage.
For accurate control, engineer has to model or simulate the device performance (device simulation) to decide the thickness of each layer, external voltage applied for a specific color, etc.
Copy right owned by OD Software Incorporated (ODSI)-the expert and tool kit provider of electronic material, device
Achieving multi color OLED device is a challenge task. One approach is to use multi layered structure. The simple one is a five layer structure which are Cathode, Red emissive layer, Green emissive layer, Blue emissive layer, and Anode layer.
One important fact to be used is that the charge carrier mobility is field effect. Usually, higher field, larger mobility. This is more effective for electron as charge carrier in organic semiconductor. Charge carrier mobility decides where hole from anode combines with the electron from the cathode in OLED device along the direction of field. This charge recombination may result in emitting light. Making use of the fact of the mobility effected by field, One can control charge recombination region by adjusting the field strength (voltage applied). As an example, a Red layer is close to the cathode layer. Applying relatively low voltage can result in lower electron mobility compared with hole. This leads to charge recombine at Red layer resulting in Red emitting light. In the same way, one can achieve different color by applying proper voltage.
For accurate control, engineer has to model or simulate the device performance (device simulation) to decide the thickness of each layer, external voltage applied for a specific color, etc.
Copy right owned by OD Software Incorporated (ODSI)-the expert and tool kit provider of electronic material, device
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