2016.04.12PolyU Develops Perovskite-Silicon Tandem Solar Cells with the World's Highest Power Conversion Efficiency

Research is funded by Miss Clarea Au (first from left) and other fundingProfessor Charles Chee Surya, Clarea Au Endowed Professor in Energy, developed perovskite-silicon tandem solar cells with 25.5% power conversion efficiency.Newly developed perovskite-silicon solar cells can reduce the cost of solar energy

The Hong Kong Polytechnic University (PolyU) has successfully developed perovskite-silicon tandem solar cells with the world's highest power conversion efficiency of 25.5% recently. Perovskite solar cells first appeared in 2009 with an efficiency of just 3.8%. With the outstanding photovoltaic properties, perovskite solar cell has become a subject of vigorous research for sustainable power generation, with researchers around the world finding new ways to increase its energy conversion efficiency. It has currently established itself as one of the most promising solar cell materials. The research team in the Department of Electronic and Information Engineering led by Professor Charles Chee Surya, Clarea Au Endowed Professor in Energy, has recently made this world record with innovative means to enhance energy conversion efficiency. With this innovation, it is estimated that solar energy can be generated at cost of HK$2.73/W, compared with HK$3.9/W at present generated by existing silicon solar cells available in the market.

As there are different wavelengths for solar energy, a combination of different materials for making solar cells would work best for energy absorption. For example, methylammonium lead tri-halide perovskite and silicon solar cells can form a complementary pair. With the perovskite solar cell functioning as a top layer, it can harvest the short wavelength photons while the bottom layer coated with silicon is designed to absorb the long wavelength photons. PolyU's research team maximizes efficiency by making use of this feature with three innovative approaches. Firstly, the team discovers a chemical process - low-temperature annealing process in dry oxygen to reduce the impact made by perovskite defects. Secondly, the team fabricates a tri-layer of molybdenum trioxide / gold / molybdenum trioxide with optimized thickness of each layer, making it highly transparent for light to go into the bottom silicon layer under perovskite layer. Finally, by mimicking the surface morphology of the rose petals, a haze film, developed by Dr Zijian Zheng of PolyU Institute of Textiles and Clothing, has been applied as the top layer of the solar panel to trap more light. All three innovative approaches help enhance energy conversion efficiency. Professor Shen Hui of Sun Yat-sen University and Shun De SYSU Institute for Solar Energy, who excelled in the fabrication high-efficiency silicon cells, was responsible for the design and fabrication of the bottom silicon cell.

PolyU research team will continue to improve the power conversion efficiency as well as the performance of large-scale fabrication of perovskite-silicon solar cells.

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PolyU-Developed Perovskite-Silicon Tandem Solar Cells Breaks Record of the World's Highest Power Conversion Efficiency

The Hong Kong Polytechnic University (PolyU) has succeeded in developing perovskite-silicon tandem solar cells which achieve the world's highest power conversion efficiency of 25.5%. The first cells of this kind appeared in 2009 with an efficiency of just 3.8%. Given its outstanding photovoltaic properties, perovskite solar cell can generate sustainable power, and so it is one of the most promising solar cell materials.

The research team in the Department of Electronic and Information Engineering, led by Professor Charles Chee Surya, Clarea Au Endowed Professor in Energy, has designed the cell with innovative means to enhance energy conversion efficiency. It is estimated that solar energy can be generated at a lower cost of HK$2.73/W, compared with HK$3.9/W generated by the existing silicon solar cells available in the market.

With different wavelengths for solar energy, a combination of various materials for making solar cells can maximize energy absorption. For instance, methylammonium lead tri-halide perovskite and silicon solar cells can form a complementary pair. With the perovskite solar cell functioning as a top layer, it can obtain the short wavelength photons while the bottom layer, coated with silicon, can absorb the long wavelength photons. PolyU's research team utilizes this feature with three innovative approaches. First, low-temperature annealing process in dry oxygen reduces the impact made by perovskite defects. Secondly, the team fabricates a tri-layer of molybdenum trioxide / gold / molybdenum trioxide with optimized thickness of each layer, turning it highly transparent for light to travel into the bottom silicon layer under perovskite layer. Lastly, by mimicking the surface morphology of the rose petals, a haze film, developed by Dr Zijian Zheng of PolyU Institute of Textiles and Clothing, has been applied as the top layer of the solar panel so as to trap more light. Professor Shen Hui of Sun Yat-sen University and Shun De SYSU Institute for Solar Energy, a specialist in the fabrication high-efficiency silicon cells, participated in the design and fabrication of the bottom silicon cell.

PolyU research team will strive to continue the cell’s advancement and improve the power conversion efficiency, as well as the performance of large-scale fabrication of perovskite-silicon solar cells.

Press Contacts

Professor Charles Chee Surya

Clarea Au Endowed Professor in Energy, Department of Electronic and Information Engineering

Email(852) 2766 6220
Emailcharles.surya@polyu.edu.hk
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