Solar panels on a roll with tool to identify nanoscopic defects

A ‘one-shot’ interferometer that rapidly spots nanoscale flaws in solar panels during manufacture could soon move from the lab to a production line after winning a government grant.

The device, which can compensate for conditions including excessive vibrations, will allow materials such as flexible solar panels to be manufactured more efficiently and economically by monitoring their quality.

Under the High Value Manufacturing Catapult scheme, Dr Feng Gao, a senior research fellow at Huddersfield University has been handed the three-year task of installing the technology at the Centre for Process Innovation (CPI).

Based in County Durham, CPI specialises in technologies such as printable electronics, including these rolls of flexible solar panels embedded with photovoltaic cells.

Researchers at Huddersfield’s EPSRC Centre for Innovative Manufacturing in Advanced Metrology have been working to improve the quality control and reliability of these flexible solar panels, developing new technologies for the detection, cleaning and repair of micro and nanoscale defects in the thin films that are vital in printed electronic products.

They have been using an award-winning Wavelength Scanning Interferometer, which can detect defects in the coatings of roll-to-roll flexible photovoltaic cells.

Dr Gao will now investigate how to employ the EPSRC Centre’s prototype instruments in the roll-to-roll production line at the Centre for Process Innovation.

‘This interferometer only needs one shot to acquire all the information for the measurement,’ he explained. ‘Generally an interferometer needs to take a few consecutive shots in order to achieve a measurement. Therefore it is sensitive to the environmental vibration.’

To achieve success, he must transfer the device from an optical lab, where it is stabilised and protected, and adapt it to embed it into a round-the-clock factory production line where the roll-to-roll films are produced at great speed, adding to the difficulty of monitoring for defects.

If successful, Dr Gao believes the technology could have an impact in other areas of manufacturing.

‘This device can be used for other on-line surface inspection,’ added Dr Gao. ‘We have other parties expressing their interest in this instrument, including micro-lens array manufacturers, and for use in additive manufacturing.’