Boffins find ways to harvest electrons to make optoelectronic devices more efficient

A University of California, Los Angeles (UCLA) research team has found a way to make optoelectronic devices more efficient by having them harvest electrons to generate current instead of heat.

London, May 5 : A University of California, Los Angeles (UCLA) research team has found a way to make optoelectronic devices more efficient by having them "harvest" electrons to generate current instead of heat.

Researchers say silicon-based optoelectronic devices will revolutionise computing and telecommunications by boosting the speed at which information can be fed through a system and the amount of data, or bandwidth, that can be processed.

While existing devices require a lot of light, and also give off unacceptable amounts of heat, these 'fast' silicon chips use light and electricity to process information and communicate in a more efficient manner.

"Performing basic optical operations in silicon, such as amplifying and modulating light, converting one wavelength to another and lasing, require an intense beam of light. This light interacts with silicon in a non-linear way, which is necessary for useful optical effects," said Bahram Jalali, head of UCLA's optoelectronics lab.

"However, pushing intense beams of light through silicon also results in a problem known as two-photon absorption. This occurs when part of the silicon's crystal lattice absorbs two photons at once, which frees more electrons to absorb still more photons. It's like a chain reaction.

"The problem is fundamental. You have to have non-linear processes, so you have to pump silicon hard. When you pump it hard, silicon becomes like a sponge - it absorbs all the light," he said.

The UCLA team will present its findings at the Conference on Lasers and Electro-Optics, in Maryland, US, on May 11, reports New Scientist.

ANI