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November
16
2022

All-perovskite tandem solar cell boasts high efficiency, record voltage
Michael Irving

Engineers have developed a new solar cell with a record voltage and (arguably) a record efficiency for its kind. The all-perovskite tandem solar cell uses two layers of perovskite that tap into different wavelengths of light, plus a special surface treatment that reduces wasted energy.

In the field of photovoltaics, perovskite is a particularly promising material that’s gunning for silicon’s crown. Not only is it great at absorbing energy from sunlight, but it’s thinner, lighter, more flexible, and easier and cheaper to manufacture.

Efficiency-wise, perovskite has shot up drastically in a little over a decade, from under 4% in 2009 to over 25% in 2021, now rivaling silicon. It works even better in so-called tandem cells, where multiple layers of materials are stacked on top of each other to harvest different wavelengths of light from the Sun. Perovskite-silicon tandem solar cells, for instance, recently passed the 30% efficiency milestone.

In the new study, a team of engineers has created and tested an all-perovskite tandem solar cell. How can a solar cell be all-perovskite but still tandem? The material’s thickness and chemical composition can be tweaked to allow it to tap into different parts of the solar spectrum, so two different versions of the material can be combined in one device.

“In our cell, the top perovskite layer has a wider band gap, which absorbs well in the ultraviolet part of the spectrum, as well as some visible light,” said Chongwen Li, co-lead author of the study. “The bottom layer has a narrow band gap, which is tuned more toward the infrared part of the spectrum. Between the two, we cover more of the spectrum than would be possible with silicon.”

Using this design, the team reported that a solar cell measuring 1 cm2 (0.15 in2) had a maximum efficiency of 27.4%, which would be a record for its type and impressive for any kind of solar cell. However, the team stops short at claiming the title, since an independent certification by NREL recorded an efficiency of 26.3% – just 0.1% short of the current official record-holder.

Where the cell did achieve a new record is in its voltage. The team measured an open-circuit voltage of 2.19 electron volts, the highest of any all-perovskite tandem solar cell.

Both of these impressive stats came thanks to tweaks made at the interface between the perovskite light-absorbing layer and the layer that carries electrons away. The team found that the electric field wasn’t consistent across the surface of the perovskite, meaning some electrons would be lost to the circuit. So the team added a thin coat of what’s called 1,3-propanediammonium (PDA), which evens out the charge of the surface.

The team says that future work will focus on boosting the solar cell’s efficiency by making the cell more stable, increasing the current, and expanding the size of the cell.

The research was published in the journal Nature.

Source: University of Toronto

I AM CHRISTOPHER CHANTRILL, a member of the international capitalist conspiracy. Both my grandfathers owned and operated import/export businesses in the early twentieth century, one in St. Petersburg, Russia, where my father was born, and the other in Kobe, Japan, where my mother was born.

I was born in India and raised and educated in England. I immigrated to the United States in 1968 and worked for many years designing and implementing utility control systems and software in Seattle.

Soon after moving to Seattle, I instinctively revolted against the suffocating left-coast culture of the Soviet of Washington, and soon came to revere the four great Germans who helped inspire the Reagan revolution: Ludwig von Mises, F.A. Hayek, Leo Strauss, and Eric Voegelin. Since then I have broadened my appreciation of “The German Turn” that has transformed the world over the last 200 years.

I have written for Liberty, FrontPageMag.com, and The American Thinker. My book Road to the Middle Class celebrates the self-governing culture of the United States in which enthusiastic Christianity, education, mutual aid, and living under law have taught generations of immigrants to rise from indigence in the countryside to a life of competence and prosperity in the city. My book An American Manifesto: Life after Liberalism tries to imagine what America would look like after the end of left-wing politics and big government.

www.christopherchantrill.com