Novel 3D solar cells to undergo testing in space

A novel 3D solar cell that was launched to the International Space Station (ISS) will be installed on the exterior of the station to study the cells' performance and their ability to withstand the rigours of space, scientists said.  An experimental module containing 18 test cells, developed by researchers at Georgia Institute of Technology (Georgia Tech), was launched to the ISS yesterday aboard SpaceX's Falcon 9

rocket from Cape Canaveral Air Force Station in Florida. In addition to testing the 3D format, the module will also study a low-cost copper-zinc-tin-sulfide (CZTS) solar cell formulation. "We want to see both the light-trapping performance of our 3D solar cells and how they are going to respond to the harshness of space," said Jud Ready, a principal research engineer at the Georgia Tech Research Institute (GTRI).

"We will also measure performance against temperature, because temperature has an influence on the performance of a solar cell," said Ready. 

Built by coating miniature carbon nanotube "towers" with a photo-absorber that captures sunlight from all angles, the 3D cells could boost the amount of power obtained from the small surface areas many spacecraft have. 

The cells would absorb light from any direction, eliminating the need for the devices to aim photovoltaics (PV) modules toward the Sun.

The PV cell experiment will be installed on the NanoRacks External Platform (NREP), where robustness of the solar cells will be studied under harsh space conditions for six months.

"The CZTS photovoltaic arrays were built using the readily available elements copper, zinc, tin and sulphur to replace rarer CIGS - copper, indium, gallium and selenium - which are used in similar thin-film solar cells," said Ready.

"The CZTS approach produces an efficient photo-absorber using earth-abundant materials that cost around a thousand times less than rare-earth elements like indium, gallium and selenium," he said.