Researchers at Nanyang Technological University (NTU) in Singapore have created a perovskite solar mini module that has recorded the highest power conversion efficiency of any panel over 10 cm2.
Perovskite materials are a hugely popular option for low cost, thin film solar cells that can be installed on roofs and buildings to generate power. Researchers have taken the efficiency of cells up to 28 percent and of tandem cells on top of a silicon cell up to 27 percent. Large area cells can be built in a number of ways, from spray coating to inkjet printing but the challenge has been to boost the efficiency of these larger modules.
The NTU researchers used a common industrial coating technique called 'thermal co-evaporation' to build solar cell modules of 21 cm2 size with record power conversion efficiencies of 18.1 per cent. The team says this is the highest recorded value reported for scalable perovskite solar cells. This thermal evaporation is an established coating technique currently used to produce electronics including Organic Light Emitting Diode (OLED) TVs.
"The best-performing perovskite solar cells have so far been realised in the laboratory at sizes much smaller than 1 cm2, using a solution-based technique called 'spin-coating'. However, when used on a large surface, the method results in perovskite solar cells with lower power conversion efficiencies. This is due to the intrinsic limitations that include defects and lack of uniformity over large areas, making it challenging for industrial fabrication methods," said Dr Annalisa Bruno, Senior Scientist at the Energy Research Institute at NTU.
"By using thermal evaporation to form the perovskite layer, our team successfully developed perovskite solar cells with the highest recorded power conversion efficiency reported for modules larger than 10 cm2. Our work demonstrates the compatibility of perovskite technology with industrial processes, and its potential for market entry.