New look for molecular photodiodes - GoFuckYourself.com

Juicy D. Links · 07-02-2004, 04:26 PM

Another good article

Scientists in Japan have made a new type of molecular photodiode, whose current switches direction depending on the wavelength of the light used to excite it. Designed by Shunsaku Kimura and colleagues at Kyoto University, the device consists of two helical peptide molecules, whose dipole moments point in opposite directions. Their technique could be used to make a wide variety of molecular electronics devices on the nanoscale

Molecular electronics has made steady progress in recent years and components made from single molecules could overcome the limits of conventional, silicon-based microelectronics. However, many challenges still need to be overcome before molecular electronic devices can become a reality, including the fact that it is difficult to integrate them into ordered structures.

The photodiode fabricated by Kimura and colleagues consists of two types of helical peptide -- long protein chains -- each of which has a different light-absorbing end-group, or chromophore. The two peptides, which are about 1 nanometre across, were anchored on a gold substrate. Such molecules are good candidates for molecular devices because they can form highly ordered self-assembled monolayers.

The Kyoto team found that when one of the chromophores was excited with light of a certain wavelength it generated an anodic photocurrent. However, when the other chromphore was excited -- with light of a different wavelength -- the current flowed in the opposite direction, towards the cathode. The reason for this behaviour is that each helical peptide has a large intrinsic dipole moment that accelerates electron transfer in the same direction in which its dipole moment is pointing. Since the two peptides have dipole moments that point in opposite directions, the current is sent in opposite directions (see figure).

"The large dipole moment of helical peptides means they could be used as modulators in many types of electronic device made on the nanoscale," Kimura told PhysicsWeb. "They could thus be useful starting materials for the coming age of molecular electronics." The team now hopes to make a molecular transistor using such peptides.

tolik · 07-02-2004, 04:34 PM

you think more then 5% people here have any idea WTF is photodiodes?

MattO · 07-02-2004, 04:35 PM

looks like the protein computer is becoming a reality

InkedUpMess · 07-02-2004, 04:38 PM

Ummmm....................................... ok

Khun · 07-02-2004, 04:53 PM

I need a stiff drink to get the blood back in my brain now....

stevecore · 07-02-2004, 05:14 PM

McDonalds employees take notes, this is how McNuggets are made if a customer asks.

07-02-2004, 04:26 PM	#1
Juicy D. Links So Fucking Banned Industry Role: Join Date: Apr 2001 Location: N.Y. -Long Island -- Posts: 122,992	New look for molecular photodiodes Another good article Scientists in Japan have made a new type of molecular photodiode, whose current switches direction depending on the wavelength of the light used to excite it. Designed by Shunsaku Kimura and colleagues at Kyoto University, the device consists of two helical peptide molecules, whose dipole moments point in opposite directions. Their technique could be used to make a wide variety of molecular electronics devices on the nanoscale Molecular electronics has made steady progress in recent years and components made from single molecules could overcome the limits of conventional, silicon-based microelectronics. However, many challenges still need to be overcome before molecular electronic devices can become a reality, including the fact that it is difficult to integrate them into ordered structures. The photodiode fabricated by Kimura and colleagues consists of two types of helical peptide -- long protein chains -- each of which has a different light-absorbing end-group, or chromophore. The two peptides, which are about 1 nanometre across, were anchored on a gold substrate. Such molecules are good candidates for molecular devices because they can form highly ordered self-assembled monolayers. The Kyoto team found that when one of the chromophores was excited with light of a certain wavelength it generated an anodic photocurrent. However, when the other chromphore was excited -- with light of a different wavelength -- the current flowed in the opposite direction, towards the cathode. The reason for this behaviour is that each helical peptide has a large intrinsic dipole moment that accelerates electron transfer in the same direction in which its dipole moment is pointing. Since the two peptides have dipole moments that point in opposite directions, the current is sent in opposite directions (see figure). "The large dipole moment of helical peptides means they could be used as modulators in many types of electronic device made on the nanoscale," Kimura told PhysicsWeb. "They could thus be useful starting materials for the coming age of molecular electronics." The team now hopes to make a molecular transistor using such peptides.

07-02-2004, 04:34 PM	#2
tolik Confirmed User Join Date: Jun 2001 Location: inside my brain Posts: 2,035	you think more then 5% people here have any idea WTF is photodiodes? __________________ LONGBUCKS-Teen, Mature, Reality, Gay sites. Free hosting (cgi/php/mysql/cron etc). FHGs. Free content.Great rebills. Support icq - 313-882-945 Webmaster friendly high recommended programs to promote (personal experience): RoyalCash-Teen ProfitX -Video SmokinCash-Amateur,Lesbo,Squirting

07-02-2004, 04:38 PM	#4
InkedUpMess Confirmed User Join Date: Feb 2004 Location: Brooklyn Posts: 368	Ummmm....................................... ok __________________ SIG TOO BIG! Maximum 120x60 button and no more than 3 text lines of DEFAULT SIZE and COLOR. Unless your sig is for a GFY top banner sponsor, then you may use a 624x80 instead of a 120x60.

07-02-2004, 04:53 PM	#5
Khun Confirmed User Industry Role: Join Date: Jun 2004 Location: TN Posts: 1,239	I need a stiff drink to get the blood back in my brain now.... __________________ Sig is on vacation... (I wish I could vacation as long as my sig has...)

07-02-2004, 04:35 PM	#3
MattO The O is for Oohhh Join Date: Feb 2003 Location: AUSTIN TEJAS Posts: 10,861	looks like the protein computer is becoming a reality

07-02-2004, 05:14 PM	#6
stevecore Confirmed User Join Date: May 2003 Posts: 6,130	McDonalds employees take notes, this is how McNuggets are made if a customer asks.