Scientists at Loughborough University are researching more efficient solar panels.
Experts are looking to increase the efficiency of CdTe modules as it has the potential to be competitive on efficiency but at a lower manufacturing cost than silicon-based modules, which use mono-crystalline silicon (c-Si).
The carbon footprint of CdTe is also half that of c-Si modules and end-of-life module recycling for CdTe modules is guaranteed.
Untreated CdTe has very low efficiency and is typically about only 1%. However, when CdTe undergoes a chlorine treatment – which involves treating CdTe with cadmium chloride at 420oC for 20 minutes – its efficiency jumps dramatically. The record cell efficiency is 22%.
Until now, how or why chlorine improves efficiency so drastically was not fully understood.
For the first time, Loughborough University’s Dr Pooja Goddard and Professor Roger Smith, along with Dr Peter Hatton and Dr Michael Watts (PhD graduates of Loughborough), have modelled the mechanism by which chlorine improves the efficiency of CdTe.
The study is a joint effort with Professor Mike Walls’ experimental research group housed at Loughborough’s Centre for Renewable Energy Systems Technology (CREST).
It is hoped the findings, published in Nature Communications, will improve understanding of how chlorine enhances electrical performance and lead to further tuning, resulting in even higher efficiencies (>25%).
This would help CdTe solar modules to produce even lower cost electricity.
To read the paper, titled ‘Chlorine activated stacking fault removal mechanism in thin film CdTe solar cells: the missing piece’, click here.
