Photovoltaic cell and battery in one - the future of solar power plants

Until now, solar power plants have required huge arrays of batteries, but soon the need for batteries may disappear. Chinese researchers have invented a device capable of "capturing" sunlight, converting it into electricity and storing it in its structure.

Photovoltaic devices that convert light energy into electricity form the backbone of alternative energy technologies. But they often have to be connected to batteries that store the generated energy, since the flow of sunlight is unstable during the day.

In a new development reported by the American Physical Society, researchers have created a device capable of simultaneously converting sunlight into electricity and storing the resulting energy. The electrons "knocked out" by light quanta can be retained by the device for at least a week, after which they begin to "leak" into the environment.

The development is based on tungsten diselenide - a semiconductor material - and strontium titanium oxide (STO) - a transparent conductor. On the surface of STO, physicists have created a two-dimensional "electron gas" (a state in which electrons move freely and independently) by treating the surface of the material with special methods. This innovative approach allows the device to acquire new properties.

Such a device is also capable of functioning as an optical memory. Information can be entered into it using a light pulse and stored until it needs to be read in the form of an electric current pulse.

A source: aps.org