Graphene innovation halves the cost of semitransparent perovskite solar cells
The power conversion efficiencies (PCEs) of the devices are around 12% when they are illuminated from Fluorine-doped Tin Oxide bottom electrodes (FTO) or the graphene top electrodes, compared with 7% of conventional semitransparent solar cells.
The researchers claim that the solar cells offer more than a 50% reduction in costs compared with the existing cost of silicon solar cells, will enable it to be widely used in the future.
With the aim of improving PCEs and reducing costs of semitransparent solar panels, PolyU researcher has developed the first-ever made semitransparent perovskite solar cells with graphene as electrode. Graphene is an ideal candidate for transparent electrodes in solar cells with high transparency, good conductivity and potentially low cost. The semitransparent feature of the solar cell enables it to absorb light from both sides, and can be widely used in windows, facades and rooftops of buildings for converting solar energy into electricity, increasing the surface area for collecting solar energy substantially.
PolyU has developed simple processing techniques for enhancing the conductivity of graphene to meet the requirement of its applications in solar cells. Firstly, the conductivity of graphene was dramatically improved by coating a thin layer of conductive polymer poly-(3,4-ethylenedioxythiophene): poly(styrenesulfonate), that was also used as an adhesion layer to the perovskite active layer during the lamination process. Secondly, to further improve the efficiency of power conversion, PolyU researchers found that by fabricating the solar cell with multilayer chemical vapor deposition graphene as top transparent electrodes, the sheet resistance of the electrode could be further reduced while maintaining the high transparency of the electrodes. Lastly, the performance of this novel invention is further optimized by improving the contact between the top graphene electrodes and the hole transport layer (spiro-OMeTAD) on the perovskite films.
PolyU’s innovation can be used for the mass production of the semitransparent perovskite solar cells with printing or roll to roll process. The semitransparent solar cells will fill the gap in the market which is not achievable by the existing solar cells dominating the market.
Study findings have been published in Advanced Materials, a leading journal in material science.
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