Australasian Science: Australia's authority on science since 1938

Sticky Tape the Key to Ultrathin Solar Cells

Scientists studying thin layers of phosphorus have found surprising properties that could open the door to ultrathin and ultralight solar cells and LEDs.

The team created single-atom thick layers of the semiconductor phosphorene by repeatedly using sticky tape to peel thinner and thinner layers of crystals from the black crystalline form of phosphorus.

“Because phosphorene is so thin and light, it creates possibilities for making lots of interesting devices, such as LEDs or solar cells,” said Dr Yuerui Lu of The Australian National University.

As well as creating much thinner and lighter semiconductors than silicon, phosphorene has light-emission properties that vary widely with the thickness of the layers, which enables much more flexibility for manufacturing.

”This property has never been reported before in any other material,” said Lu, whose study is published in Light: Science and Applications.

“By changing the number of layers we can tightly control the band gap, which determines the material’s properties, such as the colour of LED it would make. You can see quite clearly under the microscope the different colours of the sample, which tells you how many layers are there.”

Lu said that the behaviour of phosphorene in thin layers is superior to silicon, “whose surface states… prevent it being used in such a thin state”.