Carbon quantum dots (C-dots) are tiny particles, with dimensions down to a few nanometers, mainly composed of carbon, which exhibit tunable optical properties. They are able to absorb selectively solar light in a specific color range, and re-emit part of the absorbed radiation as a monochromatic light.
LSCs are “active” and colored windows, able to transform part of the solar light into electricity, thanks to tiny solar cells, placed at the edge of the slab.
− The carbon dots LSCs we studied in this work represent a major advance toward the production of low cost, high-efficiency, large-area, and scalable LSCs. Our research also gives a practical demonstration of how the understanding of carbon dots physical and optical properties can result in the improved functionality of such devices, says Alberto Vomiero, professor of experimental physics at Luleå University of Technology.
Record power conversion efficiency
The authors Alberto Vomeiro and Shujie You, both active in the research subject of experimental physics, show how synthesis of C-dots and the manufacture of C-dot base-ready luminescent solar concentrators can be used for so-called photovoltaic systems. A new form of solar cells built into a structure, rather than added later. The study, which was carried out together with other research groups in Sweden, China and Italy, shows great opportunities to produce highly efficient and environmentally friendly luminescent solar concentrators.
− The large-area C-dots LSCs in this work exhibited a record power conversion efficiency for such devices under natural sunlight illumination after coupling to silicon solar cells. Compared to conventional inorganic quantum dots (QDs) and dyes/polymers, our findings demonstrate the possibility of obtaining eco-friendly, high-efficiency, large-area carbon dots LSC through scalable production techniques, says Shujie You, assistant professor at Luleå University of Technology and says that the researchers used ordinary glass windows to generate solar energy.
− The produced C-dots are embedded in plastic film and coated on ordinary glass window, then coupled with slim solar cells, which are placed on the edge of the glass windows. The device can produce electricity using the sunlight without losing much transparency in the visible range.
A way to boost BIPV technologies
The hope is that the study will be useful for the development of so-called building-integrated photovoltaic sector, often abbreviated as BIPV.
− Replacing the conventional transparent building components such as the roof, windows and facades with slightly coloured large area carbon dots sunlight collectors without sacrificing the appearance of the building, might be a way to boost BIPV technologies for energy and environmental applications, says Alberto Vomiero.
Having their article published in one of the highest ranked journals in the field, the researchers see as a great recognition.
− Energy & Environmental Science (EES) is an international journal dedicated to publishing exceptionally important and high quality, agenda-setting research tackling the key global and societal challenges of ensuring the provision of energy and protecting our environment for the future. EES is one of the highest ranked journals in our field. Having our paper published as a cover story in EES means our research has been recognized as important and high quality by the best researchers in this field. It brings us confidence and enthusiasm to continue and boost our research in solar harvesting materials, says Shujie You.