Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button

Home > Press > Molecular Switches

Abstract:
Optoelectronic components based on a dye-sensitized TiO2 solar cell

Molecular Switches

Posted on April 24, 2006

Electronic components must continue to get smaller: Miniaturization has now reached the nanometer scale (10-9 m). In this tiny world, classic semiconductor technology is reaching its limits. We now need switches and other devices whose dimensions are on the scale of individual molecules. The difficulty with this is in the addressability and compatibility of molecular systems with the available nanoelectronic components. Until now, all molecular systems require at least one step in which a solution must be injected into the system and then rinsed out again, which is time-consuming.

L. Furtado, K. Araki, H. E. Toma, and co-workers at the University of São Paulo in Brazil describe for the first time an optoelectronic molecular gate that directly absorbs light and gives off electrical impulses.

The gate consists of a glass electrode onto which a thin, nanocrystalline film of TiO2 is deposited. A dye, in this case a cluster of three ruthenium–pyrazinecarboxylate complexes, is adsorbed to this surface. A platinum counter electrode is used, and the space between the electrodes is filled by an electrolyte solution of I 3-/I2 in CH3CN.

When this gate is irradiated with light, electrons are excited, which leads to charge separation and a flow of current. The direction of the current changes depending on the wavelength of the light irradiating the system: at 350 nm, the electrons flow from the Pt electrode to the glass electrode; at 420 nm, they flow the other way.

At 350 nm, the TiO2 layer absorbs the light and gives off electrons to the underlying glass electrode. To compensate, the corresponding number of electrons is removed from the ruthenium cluster, which replaces them with electrons from the Pt electrode. At 420 nm, however, the ruthenium complexes are induced to give off electrons to the Pt electrode, which are re-supplied from the TiO2 layer.

The result is a switch that is not only turned on and off by light, but whose signal can change direction on the basis of the wavelength of light used.

####


Author: Koiti Araki, Universidade de São Paulo (Brazil), www2.iq.usp.br/docente/?id=koiaraki

Title: TiO2-Based Light-Driven XOR/INH Logic Gates

Angewandte Chemie International Edition, 2006, 45, No. 19, 3143–3146, doi: 10.1002/anie.200600076

Contact:
Editorial office:
angewandte@wiley-vch.de

or David Greenberg (US)
dgreenbe@wiley.com

or Julia Lampam (UK)
jlampam@wiley.co.uk

Copyright © Angewandte Chemie

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

Nanoelectronics

Supersonic spray yields new nanomaterial for bendable, wearable electronics: Film of self-fused nanowires clear as glass, conducts like metal November 23rd, 2016

What a twist: Silicon nanoantennas turn light around: The theoretical results will allow scientists to design nanodevices with extraordinary features for use in optoelectronics November 21st, 2016

2-D material a brittle surprise: Rice University researchers finds molybdenum diselenide not as strong as they thought November 14th, 2016

UCR researchers discover new method to dissipate heat in electronic devices: By modulating the flow of phonons through semiconductor nanowires, engineers can create smaller and faster devices November 13th, 2016

Announcements

Shape matters when light meets atom: Mapping the interaction of a single atom with a single photon may inform design of quantum devices December 4th, 2016

UTSA study describes new minimally invasive device to treat cancer and other illnesses: Medicine diffusion capsule could locally treat multiple ailments and diseases over several weeks December 3rd, 2016

Novel Electrode Structure Provides New Promise for Lithium-Sulfur Batteries December 3rd, 2016

Research Study: MetaSOLTM Shatters Solar Panel Efficiency Forecasts with Innovative New Coating: Coating Provides 1.2 Percent Absolute Enhancement to Triple Junction Solar Cells December 2nd, 2016

NanoNews-Digest
The latest news from around the world, FREE




  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project