Article last updated on: Dec 01, 2020

What are perovskite?

Perovskites are a class of materials that share a similar structure, which display a myriad of exciting properties like superconductivity, magnetoresistance and more. These easily synthesized materials are considered the future of solar cells, as their distinctive structure makes them perfect for enabling low-cost, efficient photovoltaics. They are also predicted to play a role in next-gen electric vehicle batteries, sensors, lasers and much more.

How does the PV market look today?

In general, Photovoltaic (PV) technologies can be viewed as divided into two main categories: wafer-based PV (also called 1st generation PVs) and thin-film cell PVs. Traditional crystalline silicon (c-Si) cells (both single crystalline silicon and multi-crystalline silicon) and gallium arsenide (GaAs) cells belong to the wafer-based PVs, with c-Si cells dominating the current PV market (about 90% market share) and GaAs exhibiting the highest efficiency.

Perovskite solar cell market image

Thin-film cells normally absorb light more efficiently than silicon, allowing the use of extremely thin films. Cadmium telluride (CdTe) technology has been successfully commercialized, with more than 20% cell efficiency and 17.5% module efficiency record and such cells currently hold about 5% of the total market. Other commercial thin-film technologies include hydrogenated amorphous silicon (a-Si:H) and copper indium gallium (di)selenide (CIGS) cells, taking approximately 2% market share each today. Copper zinc tin sulphide technology has been under R&D for years and will probably require some time until actual commercialization.

What is a perovskite solar cell?

An emerging thin-film PV class is being formed, also called 3rd generation PVs, which refers to PVs using technologies that have the potential to overcome current efficiency and performance limits or are based on novel materials. This 3rd generation of PVs includes DSSC, organic photovoltaic (OPV), quantum dot (QD) PV and perovskite PV.



A perovskite solar cell is a type of solar cell which includes a perovskite structured compound, most commonly a hybrid organic-inorganic lead or tin halide-based material, as the light-harvesting active layer. Perovskite materials such as methylammonium lead halides are cheap to produce and relatively simple to manufacture. Perovskites possess intrinsic properties like broad absorption spectrum, fast charge separation, long transport distance of electrons and holes, long carrier separation lifetime, and more, that make them very promising materials for solid-state solar cells.

Perovskite solar cell image

Perovskite solar cells are, without a doubt, the rising star in the field of photovoltaics. They are causing excitement within the solar power industry with their ability to absorb light across almost all visible wavelengths, exceptional power conversion efficiencies already exceeding 20% in the lab, and relative ease of fabrication. Perovskite solar cells still face several challenge, but much work is put into facing them and some companies, are already talking about commercializing them in the near future.

What are the advantages of Perovskite solar cells?

Put simply, perovskite solar cells aim to increase the efficiency and lower the cost of solar energy. Perovskite PVs indeed hold promise for high efficiencies, as well as low potential material & reduced processing costs. A big advantage perovskite PVs have over conventional solar technology is that they can react to various different wavelengths of light, which lets them convert more of the sunlight that reaches them into electricity.

Moreover, they offer flexibility, semi-transparency, tailored form factors, light-weight and more. Naturally, electronics designers and researchers are certain that such characteristics will open up many more applications for solar cells.

What is holding perovskite PVs back?

Despite its great potential, perovskite solar cell technology is still in the early stages of commercialization compared with other mature solar technologies as there are a number of concerns remaining.

One problem is their overall cost (for several reasons, mainly since currently the most common electrode material in perovskite solar cells is gold), and another is that cheaper perovskite solar cells have a short lifespan. Perovskite PVs also deteriorate rapidly in the presence of moisture and the decay products attack metal electrodes. Heavy encapsulation to protect perovskite can add to the cell cost and weight. Scaling up is another issue - reported high efficiency ratings have been achieved using small cells, which is great for lab testing, but too small to be used in an actual solar panel.

A major issue is toxicity - a substance called PbI is one of the breakdown products of perovskite. This is known to be toxic and there are concerns that it may be carcinogenic (although this is still an unproven point). Also, many perovskite cells use lead, a massive pollutant. Researchers are constantly seeking substitutions, and have already made working cells using tin instead. (with efficiency at only 6%, but improvements will surely follow).

What’s next?

While major challenges indeed exist, perovskite solar cells are still touted as the PV technology of the future, and much development work and research are put into making this a reality. Scientists and companies are working towards increasing efficiency and stability, prolonging lifetime and replacing toxic materials with safer ones. Researchers are also looking at the benefits of combining perovskites with other technologies, like silicon for example, to create what is referred to as “tandem cells”.

Commercial activity in the field of perovskite PV

In September 2015, Australia-based organic PV and perovskite solar cell (PSC) developer Dyesol declared a major breakthrough in perovskite stability for solar applications. Dyesol claims to have made a significant breakthrough on small perovskite solar cells, with “meaningful numbers” of 10% efficient strip cells exhibiting less than 10% relative degradation when exposed to continuous light soaking for over 1000 hours. Dyesol was also awarded a $0.5 million grant from the Australian Renewable Energy Agency (ARENA) to commercialize an innovative, very high efficiency perovskite solar cell.

Also in 2015, Saule Technologies signed an investment deal with Hideo Sawada, a Japanese investment company. Saule aims to combine perovskite solar cells with other currently available products, and this investment agreement came only a year after the company was launched.

In October 2020, Saule launched sunbreaker lamellas equipped with perovskite solar cells. The product is planned to soon be marketed across across Europe and potentially go global after that.

In August 2020, reports out of China suggested that a perovskite photovoltaic cell production line has gone into production in Quzhou, east China's Zhejiang Province. The 40-hectare factory was reportedly funded by Microquanta Semiconductor and expected to produce more than 200,000 square meters of photovoltaic glass before the end of 2020.

In September 2020, Oxford PV's Professor Henry Snaith stated that the Company's perovskite-based solar cells are scheduled to go on sale next year, probably by mid 2021. These will be perovskite solar cells integrated with standard silicon solar cells.

The latest perovskite solar news:

Researchers use a 2D perovskite passivation layer as an electron blocking layer in 18.5%-efficient carbon-electrode perovskite solar cell

Researchers from Fraunhofer Institute for Solar Energy Systems ISE, EPFL, Korea Basic Science Institute (KBSI) and Morocco's Abdelmalek Essaadi University have developed a perovskite solar cell with a carbon electrode that achieved 18.5% efficiency.

Electron blocking for 18.5%-efficient carbon-electrode perovskite solar cell imageSchematic diagram of the investigated low-temperature carbon electrode-based PSC with 3D/2D perovskite treated by OAI. Image from study

The solar cell also reportedly retained 82% of their efficiency after 500 hours of continuous illumination. The cell is produced via all low-temperature processes that could likely be scaled into low-cost, large-scale manufacturing – making the approach attractive despite achieving lower efficiency than record-setting cells.

Plasmonic Au nanorods enable semitransparent perovskite solar cells with over 13% efficiency

Researchers from the Singapore-HUJ Alliance for Research and Enterprise (SHARE) and Nanyang Technological University have developed semi-transparent perovskite solar cells with over 13% efficiency and 27% transparency using plasmonic Au nanorods.

Semitransparent Perovskite Solar Cells with > 13% Efficiency and 27% Transparency Using Plasmonic Au Nanorods image

Semitransparent hybrid perovskites can open the door to applications in smart windows and building-integrated photovoltaics (BIPV). One route towards semitransparency is thinning the perovskite film, which has several benefits like cost efficiency and reduction of lead. However, this tends to result in reduced light absorbance. To compromise this loss, it is possible to incorporate plasmonic metal nanostructures, which can trap incident light and locally amplify the electromagnetic field around the resonance peaks.

Researchers design ionic liquid-based perovskite solar cell with 22.86% efficiency

Researchers from EPFL, Tianjin University, Nanjing Tech University, The University of Tokyo, Shanghai University and Toyota Motor Corporation have used ionic liquids (ILs) with halide anions as additives to improve the performance and stability of a perovskite solar cell.

Ionic liquid-based perovskite solar cell with 22.86% efficiency imageImage from study in Cell Reports Physical Science

Ionic liquids are viewed as a "greener" alternative to organic solvents due to their lower volatility and flammability, as well as to their wide liquid-state window.

Researchers use swelling-induced crack propagation method to make perovskite microcells for colored solar windows

Researchers from South Korea's Institute for Basic Science (IBS), Gwangju Institute of Science and Technology and Korea University have developed perovskite micro cells with a power conversion efficiency of 20.1% that can be used in colored solar windows.

Korean team makes perovskite microcells for solar windows imagethe colored solar window with the metal–insulator–metal (MIM) resonant structure. The inset shows a cross-sectional view of the perovskite microcell in the colored solar window. Image from Nature Communications

The devices were built using a lift-off-based patterning approach based on swelling-induced crack propagation.

Perovskite-organic tandem solar cells with indium oxide interconnects display impressive efficiency

A group of scientists from the University of Wuppertal, the University of Tübingen, the University of Potsdam, HZB, Max Planck Institute and the University of Cologne in Germany recently developed a perovskite-organic tandem solar cell with optimized charge extraction, a high open-circuit voltage and a thickness of just 1 µm.

The tandem configuration includes a narrow-bandgap organic subcell with a p-i-n-type architecture based on the polymer PM6 and molybdenum oxide (MoOx) as the hole extraction layer (HEL). The cell has a power conversion efficiency of 17.5%, an open-circuit voltage of 0.87 V, a short-circuit current of 26.7 mA cm−², and a fill factor of 75%. The wide-bandgap perovskite subcell was built with a perovskite known as FA0.8Cs0.2Pb(I0.5Br0.5)3, with an efficiency of 16.8%, an open-circuit voltage of 1.34 V, a short-circuit current of 15.6 mA cm−², and a fill factor of 81%.