solar cells tagged posts

Mr. Zafer Hawash setting up the hanging mercury drop electrode system for conductivity measurement. Credit: Image courtesy of Okinawa Institute of Science and Technology Graduate University – OIST

Researchers have clarified the relationship between air exposure and enhanced electric proprieties in perovskite solar cells. Perovskite solar cells are the rising star in the photovoltaic landscape. Since their invention, <10 years ago, their efficiency has doubled twice and it is now over 22% – an astonishing result in the renewable energy sector. Taking the name ‘perovskite’ from the light-harvesting layer that characterizes them, these solar cells are lighter, cheaper, and more flexible than the traditional crystalline silicon-based cells.

Perovskite solar cells are usually exposed to ambient...

A semi-transparent dye-sensitized solar cell with inkjet-printed photovoltaic portraits of the Aalto researchers (Ghufran Hashmi, Merve Özkan, Janne Halme) and a QR code that links to the original research paper. Credit: Image courtesy of Aalto University

Solar cells have been manufactured already for a long from inexpensive materials with different printing techniques. Especially organic solar cells and dye-sensitized solar cells are suitable for printing. “We wanted to take the idea of printed solar cells even further, and see if their materials could be inkjet-printed as pictures and text like traditional printing inks,” says University Lecturer Janne Halme.

When light is absorbed in an ordinary ink, it generates heat...

Biomimetics: the epidermis of a rose petal is replicated in a transparent layer which is then integrated into the front of a solar cell. Credit: Illustration: Guillaume Gomard, KIT

Scientists increase the efficiency of solar cells by replicating the structure of petals. With a surface resembling that of plants, solar cells improve light-harvesting and thus generate more power. Scientists of KIT reproduced the epidermal cells of rose petals that have particularly good antireflection properties and integrated the transparent replicas into an organic solar cell. This resulted in a relative efficiency gain of 12%.

Photovoltaics works in a similar way as the photosynthesis of plants...

Plexcitons travel for 20,000 nanometers, a length which is on the order of the width of human hair. Graphic by Joel Yuen-Zhou

Scientists at UC SD, MIT and HarvardU have engineered “topological plexcitons,” energy-carrying particles that could help make possible the design of new kinds of solar cells and miniaturized optical circuitry. Within the Lilliputian world of solid state physics, light and matter interact in strange ways, exchanging energy back and forth between them.

“When light and matter interact, they exchange energy,” explained Assistant/Prof. Joel Yuen-Zhou. “Energy can flow back and forth between light in a metal (so called plasmon) and light in a molecule (so called exciton)...