How perovskite solar cells could benefit from a makeover

Perovskites and the mullet hairstyle have more in common than one might think. Both have traditionally attempted a vexing blend of practicality and capriciousness and, perhaps as a consequence, both have struggled to gain their place in the sun.

Now that these parallels have been highlighted, they may seem obvious in retrospect. But it took a group of researchers at the Queensland University of Technology (QUT) in Australia to spot the potential of linking hairstyles to perovskite materials — to produce something more enduring than either one could produce alone.

Widely expected to become the successor to monocrystalline silicon in future solar cells, perovskites are comparatively lightweight materials that can be manufactured as flexible films, making them suitable for an array of new solar energy-generating applications — from clothing to tents and spacecraft. Like the mullet, however, perovskites have a “business up front, party in the back” quality to them. Their crystalline structure can become a bit unstable when it comes in contact with moisture, which has been a barrier to broader commercialization.

It turns out that the wild side exhibited by both mullets and perovskite solar cells could be resolved with a few snips of hair off the back.

iStock.com/EzumeImages

Professor Hongxia Wang, who led the QUT research, got the notion of freshening up perovskites with a new haircut after a QUT colleague transformed hair clippings into carbon nanodots by breaking down the hairs and then burning them at 240 °C to create flexible displays.

Using hair clippings gathered from a barbershop in Brisbane, the researchers developed carbon nanodots that they incorporated into perovskite solar cells. The dots were found to confer an armor-like framework that protected the cell from moisture and other environmental factors — to make them a more stable source of solar energy.

A paper that Wang’s team published in the Journal of Materials Chemistry A effectively reported that “a little off the back” could enable the researchers to develop more stable perovskite photovoltaic cells that achieve an impressive maximum power-conversion efficiency of 20.22%.

Who says style over substance has to be a bad thing?