High-performance semitransparent polymer solar cells floating on water: Rational analysis of power generation, water evaporation and algal growth

• Published in: Nano energy 2020-11, Vol.77, p.105111, Article 105111
• Main Authors: Zhang, Nan, Jiang, Tong, Guo, Cui, Qiao, Lifang, Ji, Qing, Yin, Luqi, Yu, Liangmin, Murto, Petri, Xu, Xiaofeng
• Format: Article
• Language: English
• Subjects: Algal growth; Floating photovoltaic cells; Organic photovoltaic cells; Semitransparent polymer solar cells; Water evaporation
• ISSN: 2211-2855
• DOI: 10.1016/j.nanoen.2020.105111

Compared to conventional ground-mounted photovoltaic (PV) cells, floating photovoltaic (FPV) cells open new opportunities for scaling-up solar power generation, especially in highly populated countries that may have competing uses for the available land. Large-scale FPV projects normally deploy old-fashioned crystalline silicon panels that are brittle and difficult to integrate. Polymer solar cells (PSCs) are regarded as a newer and more versatile concept that make quite a splash today. High absorption coefficients, thin active layers and tunable absorption spectra through a synergy of molecular and device engineering promote extensive research on the integration of semitransparent polymer solar cells (ST-PSCs) with smart architecture to deliver both practical and aesthetic benefits. In this work, we propose a new concept of extending ST-PSCs to the field of FPV cells and explore the potential of regulating aquatic environments and organisms. Three groups of high-performance ST-PSCs are fabricated. Maximum efficiency of 13% and average visible transmittance over 20% deliver an optimum trade-off between power generation and transparency among the best-performing ST-PSCs. We develop new experimental approaches and propose a feasibility study on the water evaporation and algal growth by placing the large-area ST-PSCs on bodies of water. To the best of our knowledge, we demonstrate for the first time that the specific transmittance windows with controlled light intensities generated by the ST-PSCs are capable of regulating water evaporation and algal growth, which provides insight into responsible scale-up of FPVs instead of simply blocking the sunlight. The new functions of ST-PSCs pave an intriguing prospect of developing ST-PSCs for practical FPV applications in the near future. [Display omitted] •Efficient photo-to-electricity conversion and optimum transparency of semitransparent polymer solar cells.•A quantitative study on employing semitransparent polymer solar cells as thermal barriers on bodies of water.•The first report on evaluating semitransparent polymer solar cells as regulators of algal growth in bodies of water.