Greatly Improved Solar Cells

Apr 21, 2004
PbSeNQD

Victor Klimov and Richard Schaller at Los Alamos National Laboratory have enhanced the phenomenon called "impact ionization," which can significantly improve the efficiency of the conversion of solar energy to electrical current. Normally, an incident photon striking a semiconductor produces an electron-hole pair plus a bit of heat. By using sub-10-nm sized nanoparticles made of lead and selenium atoms, the Los Alamos scientists encourage the interaction to spawn a second exciton instead of the heat (see picture, which shows hi-resolution TEM image of epitaxially fused PbSe NanoQuantumDot pair.

Greatly improved solar cells might result from the use of a photophysical process in which for each incident solar photon not one but two excitons (electron-hole pairs) are created, says Physics News Update. As with photosynthesis what happens in a solar cell is the conversion of light energy into a small current of electrons; in plants the freed electrons helps to build glucose; in solar cells the currents are collected in the form of electricity.

Although they haven't yet built a working solar cell, they are the first to demonstrate the efficacy of getting the PbSe nanocrystals to render more photo-current. Implementing the new process might result in efficiency gains of more than 35% in the conversion of light to current. (Physical Review Letters, upcoming article)

See also the group website.


Explore further: Flower-like magnetic nanoparticles target difficult tumors

add to favorites email to friend print save as pdf

Related Stories

Let's send a private mission to Europa, expert says

Feb 09, 2015

Jupiter's icy moon Europa puzzles astrobiologists and sparks the imagination of extraterrestrial life seekers. It is believed that the moon has a subsurface ocean of liquid water, where life could possibly ...

Using solar energy to improve desalination process

Feb 04, 2015

An Aston University academic has proposed a new process to decompose waste desalination brine using solar energy, neutralising ocean acidity and reducing damaging environmental impacts.

Graphene multiplies the power of light

Jan 19, 2015

Could graphene turn light to electricity? Scientists have shown that graphene can convert a single photon into multiple electrons, showing much promise for future photovoltaic devices.

Recommended for you

Electrons moving along defined snake states

6 hours ago

Physicists at the University of Basel have shown for the first time that electrons in graphene can be moved along a predefined path. This movement occurs entirely without loss and could provide a basis for ...

New nanodevice defeats drug resistance

23 hours ago

Chemotherapy often shrinks tumors at first, but as cancer cells become resistant to drug treatment, tumors can grow back. A new nanodevice developed by MIT researchers can help overcome that by first blocking ...

Glass coating improves battery performance

Mar 02, 2015

Lithium-sulfur batteries have been a hot topic in battery research because of their ability to produce up to 10 times more energy than conventional batteries, which means they hold great promise for applications ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.