Perovskite-based Solar Cells: The Future of Solar Power Technology in the UK

one week ago by Sam Holland

Against the backdrop of climate change and rising global emissions from fossil fuels, Europe, like the rest of the world, is grappling with the urgent need to implement renewable technology to meet its current and future energy demands.

That's not to say, however, that the renewables industry in Europe isn't already expanding. The Guardian reports that solar power generated in the United Kingdom grew from almost nil to nearly 11 Gigawatts in less than seven years.

Cost Constraints and the Photovoltaic Industry

For a long time, the photovoltaic (PV) industry was on the back burner of research and funding targeted at renewable energy implementation due to high costs of producing PV cells and the lack of tax reliefs and subsidies for PV research.

With new research into cheaper and more efficient materials for photovoltaic cells, the industry is once again showing promise, considering new developments in the United Kingdom.

Before now, the leading materials for photovoltaic cells were Cadmium Tellurium CdTe, Copper indium gallium selenide (CIGS), and Gallium Arsenide (GaAs), which are expensive. Crystalline Silicon, relatively cheaper than the two, has the problem of low combined cell efficiency. Since researchers discovered how to improve PV efficiency by combining Silicon with a new material—Perovskite—all that has changed.

Image courtesy of Bigstock.

About Perovskite

Perovskite is a naturally occurring material with the same chemical structure as calcium titanate (CaTiO3). Although Perovskite has been in existence for a long time—it was first found in a mountain range in Germany as far back as 1839—its benefits to the renewable energy industry have only recently been demonstrated.

In 2012, a team of scholars led by Professor Henry J. Snaith made history with a thin film of Perovskite on a single-junction device that achieved 10.9% efficiency on exposure to sunlight.

A graph comparing Perovskite power conversion efficiency with other PV materials. Image courtesy of Ossila.

Benefits of Perovskite Over Other PV technologies

  1. Perovskite has a unique crystalline structure which gives it superconductivity, ferroelectricity, and magnetoresistance properties. These make it a material of choice for scientists to research its viability as a base material for optoelectronic devices.
  2. Perovskite is relatively cheap to source when compared to other optoelectronic materials like crystalline Silicon, CIGS, and Gallium Arsenide (GaAs).
  3. It is compatible with a variety of substrates including glass and flexible materials. This means that it is highly integrable on many different surfaces—think wrap-around Perovskite-based solar cells on flexible aluminium roofing, or in a foldable/rollable form.
  4. A smaller surface area of Perovskite than silicon is needed to achieve the same cell efficiency. Dr. Zonghao Liu, a scholar at the Okinawa Institute of Science and Technology Graduate University in Japan, recently demonstrated how a 1-micron thick Perovskite layer applied on a substrate considerably extended the working life of a solar cell.
  5. Perovskite’s structure can be replicated artificially on an experimental or commercial scale and still retain the same excellent chemical and electrical properties as naturally-sourced Perovskite.
  6. Unlike crystalline Silicon and other PV materials, Perovskite deposition on a substrate does not require heat, minimising manufacturing costs.

The Limitations of Perovskite

The main drawback with Perovskite is long-term degradation.

Unfortunately, Perovskite is not resistant to water in the same way as crystalline Silicon, for example. The material also contains trace amounts of lead, and this raises some concern about its long-term impact on the environment.

Pioneering Perovskite-based Research and Innovation

Today, in the United Kingdom, engineers at Oxford PV have developed the next generation of solar-efficient cells for commercial and industrial uses which use Perovskite as a base material, saving high costs associated with materials such as CdTe, CIGS, and the ultra-efficient Gallium arsenide (GaAs) cells.

Oxford PV is a cutting-edge tech company that is home to a bevy of scientists, engineers, and researchers who are diving deep into the science behind its photoelectronic properties and harnessing the new material for cost-effective production of PV solar cells.

An example of a (hexagonal) PV panel. Image courtesy of Max Pixel.

The Efficiency of Perovskite

In 2018, Oxford PV, U.K., made bold claims that its Perovskite solar cells would achieve 30% efficiency by the year 2020, and they have stats to back up their capacity to implement it. In the same year, the tech company demonstrated a record-breaking 23.7% conversion efficiency using a solar cell manufactured by depositing a 1-Cm2 thick layer of Perovskite on Silicon.

Oxford PV currently serves a huge European renewables market and is poised to become one of the largest producers of Perovskite-based solar cells in the world.

Also, strategic investments secured from big companies like Equinor and Legal & General Capital, as well as funding from the European Investment Bank, could see the technology commercialised as early as 2020.

Image courtesy of Bigstock.

Final Thoughts

There is still a lot of research and investment required to commercialise Perovskite-based solar cells in Europe. However, there is already an overwhelming amount of evidence that Perovskite could be the future of photovoltaic technology with its improved efficiency and cheaper costs of sourcing and production.