Researchers hit new world efficiency record with perovskite solar cells

July 25, 2017
Current density-voltage (J-V) curves and photovoltaic parameters of the best-performing small and large PSCs and device reproducibility. Credit: UNIST

A recent study, affiliated with UNIST finds key to produce a new cost-efficient way to produce inorganic-organic hybrid perovskite solar cells (PSCs) which sets a new world-record efficiency performance of 22.1 % in small cells and 19.7 percent in 1-square-centimeter cells.

This breakthrough comes from a research, conducted by Distinguished Professor Sang-Il Seok of Energy and Chemical Engineering at UNIST in collaboration with Professor Jun Hong Noh of Korea Research Institute of Chemical Technology and Professor Eun Kyu Kim of Hanyang University who both partook as co-authors of the study.

A key feature of this technology is its ability to fix the dominating defect in -halides, which is known to decrease the photoelectric . Their results, published online in the June 30th issue of the prestigious journal Science, demonstrates that careful control of the growth conditions of perovskite layers with management of deficient halide anions is essential for realizing high-efficiency thin-film PSCs based on lead-halide-perovskite absorbers.

"This study can improve the current record efficiency of perovskite solar from 20.1% to 22.1%," says Professor Seok. "This will accelerate the commercialization of the low-cost, high-performance perovskite solar cells."

A perovskite is an unique crystal structure, consisting of formamidinium with multiple cations and mixed halide anions. A (PSC) is a type of solar cell, which includes the perovskite structured compound, most commonly a hybrid organic-inorganic lead or tin halide-based material, as the light-harvesting active .

An organic-inorganic hybrid PSC is a type of solar cell, which includes the perovskite structured compound, as the light-harvesting active layer. Such devices have inspired much research interest owing to their applications in high-efficiency solar cells and light emission. Indeed, these solar cells not only show relatively high photovoltaic energy conversion efficiencies (above 22%), but can be also easily fabricated using cheap inorganic-organic perovskite compounds.

The formation of a dense and uniform thin layer on the substrates is crucial for the fabrication of high-performance PSCs. The concentration of defect states, which reduce a cell's performance by decreasing the open-circuit voltage and short-circuit current density, needs to be as low as possible.

The research team reports that careful control of the growth conditions of perovskite layers with management of deficient halide anions is essential for realizing high-efficiency thin-film PSCs based on lead-halide-perovskite absorbers.

In their study, the research team demonstrated the introduction of additional iodide ions into the organic cation solution, which are used to form the perovskite layers through an intramolecular exchanging process, decreases the concentration of deep-level defects. The result showed that the defect-engineered thin perovskite layers enable the fabrication of PSCs with a certified power conversion efficiency of 22.1% in small cells and 19.7% in 1-square-centimeter cells.

The energy conversion efficiency of those PSCs with reduced defects is 22.1% and has been officially certified by the National Renewable Energy Laboratory (NREL).

"The key to manufacturing high-performance solar cells to reduce defects in materials that generate energy loss when converting sunlight to electricity," says Professor Seok. "Our study presents a new method that suppresses the formation of deep-level defects, thereby setting a new record efficiency for PSCs."

Explore further: Next generation perovskite solar cells with new world-record performance

More information: Woon Seok Yang et al, Iodide management in formamidinium-lead-halide–based perovskite layers for efficient solar cells, Science (2017). DOI: 10.1126/science.aan2301

Related Stories

Toward 'greener,' inexpensive solar cells

September 28, 2016

Solar panels are proliferating across the globe to help reduce the world's dependency on fossil fuels. But conventional panels are not without environmental costs, too. Now scientists are reporting in the Journal of the American ...

New way to make low-cost solar cell technology

November 14, 2016

Researchers at ANU have found a new way to fabricate high efficiency semi-transparent perovskite solar cells in a breakthrough that could lead to more efficient and cheaper solar electricity.

Semi-transparent perovskite solar cells for solar windows

May 22, 2017

Scientists are exploring ways to develop transparent or semi-transparent solar cells as a substitute for glass walls in modern buildings with the aim of harnessing solar energy. But this has proven challenging, because transparency ...

New efficiency record for low-cost solar cell

April 4, 2017

Researchers at The Australian National University (ANU) have achieved a new record efficiency for low-cost semi-transparent perovskite solar cells in a breakthrough that could bring down the cost of generating solar electricity.

Recommended for you

Volvo to supply Uber with self-driving cars (Update)

November 20, 2017

Swedish carmaker Volvo Cars said Monday it has signed an agreement to supply "tens of thousands" of self-driving cars to Uber, as the ride-sharing company battles a number of different controversies.

New method analyzes corn kernel characteristics

November 17, 2017

An ear of corn averages about 800 kernels. A traditional field method to estimate the number of kernels on the ear is to manually count the number of rows and multiply by the number of kernels in one length of the ear. With ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.