Shining a little light changes metal into semiconductor

Shining a little light changes metal into semiconductor

This image shows how electrons in the gold nanorods get excited when exposed to light, then are absorbed into a thin film of zinc oxide, changing the properties of the composite from a metal into a semiconductor. Credit: ACS Applied Materials & Interfaces.

With funding from the Washington University International Center for Advanced Renewable Energy and Sustainability (I-CARES), Parag Banerjee, PhD, and Srikanth Singamaneni, PhD, and both assistant professors of materials science, brought together their respective areas of research.

Singamaneni's area of expertise is in making tiny, pebble-like nanoparticles, particularly gold nanorods. Banerjee's area of expertise is making thin films. They wanted to see how the properties of both materials would change when combined.

The research was published online in August in ACS Applied Materials & Interfaces.

The research team took the gold nanorods and put a very thin blanket of zinc oxide, a common ingredient in sunscreen, on top to create a composite. When they turned on light, they noticed that the composite had changed from one with metallic properties into a semiconductor, a material that partly conducts current. Semiconductors are commonly made of silicon and are used in computers and nearly all electronic devices.

"We call it metal-to-semiconductor switching," Banerjee says. "This is a very exciting result because it can lead to opportunities in different kinds of sensors and devices."

Banjeree says when the metallic gold nanorods are exposed to light, the electrons inside the gold get excited and enter the zinc oxide film, which is a semiconductor. When the zinc oxide gets these new electrons, it starts to conduct electricity.

"We found out that the thinner the film, the better the response," he says. "The thicker the film, the response goes away. How thin? About 10 nanometers, or a 10 billionth of a meter."

Other researchers working with solar cells or photovoltaic devices have noticed an improvement in performance when these two materials are combined, however, until now, none have broken it down to discover how it happens, Banerjee says.

"If we start understanding the mechanism for charge conduction, we can start thinking about applications," he says. "We think there are opportunities to make very sensitive sensors, such as an electronic eye. We are now looking to see if there is a different response when we shine a red, blue or green light on this material."

Banerjee also says this same technology can be used in solar cells.

Welcome to SUV System Ltd!

SUV System Ltd is ISO 90012008 Certified electronics distributor with 10 years of experiences.

We have built up long term business relationship with about many companies which are stockers and authorized agents. we have a steady and reliable supply to meet customer's demands to the greatest extent .Confidently, we are able to lower your cost and support your business with our years of professional service.

SUV System Ltd is Electronic Components Distributor Supplies,Find Quality Electronic Components Supplies Products IC(Integrated Circuits),Connectors,Capacitor,Resistors,Diodes,Transistors,LED at Suvsystem.com. Sourcing Other Energy, Environment, Excess Inventory Products from Manufacturers and Suppliers at Suvsystem.com

Electronic Components distributor:http://www.suvsystem.com

Connectors Distributor:http://www.suvsystem.com/l/Connectors-1.html

IC Distributor:http://www.suvsystem.com/l/IC(Integrated-Circuits)-1.html

LED Distributor:http://www.suvsystem.com/l/LED-1.html

Capacitor Distributor:http://www.suvsystem.com/l/Capacitor-1.html

Transistor Distributor:http://www.suvsystem.com/l/Transistors-1.html

Resistor Distributor:http://www.suvsystem.com/l/Resistors-1.html

Diode Distributor:http://www.suvsystem.com/l/Diodes-1.html

SUV System Ltd insists on the managing faith ofsincereness,speciality,foresight, win-win,so we build up stable-relationship customers located all over the world, including the States, Europe, Argentina, UAE, Malaysia, Australia,and India etc

we are focus on the following fields,and hope we can help you.

Metal Can Packages Transistors IR transistor INTERSIL IC NEC Diodes Civil IC Thin Film Resistors HARRIS IC Texas Instruments(TI) IC PANASONIC Resistors Zener Diodes LITTELFUSE Diodes IR Diodes IDT IC SANYO IC TOSHIBA Diodes Infineon Technologies Transistors Electronic News TDK IC NEC Transistors Low Ohmic Resistors Industrial IC PANASONIC VISHAY IC MOTOROLA IC Xilinx IC AD IC About US ELPIDA IC LED part Discrete Semiconductor Transistors Resistors Dialight LED NXP Diodes Diodes Inc Multi-units Transistors Microchip IC Chip Ferrite Beads Switching Diodes components INFLNEON Diodes
http://www.suvsystem.com/a/5632.aspx