Article last updated on: Feb 16, 2019

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.

The latest perovskite solar news:

A new manufacturing method based on pre-nucleation yields efficient perovskite solar cells

Researchers from Peking University in China have developed a manufacturing method for perovskite solar cells using a pre-nucleation technique. Compared to traditional solvent dripping methods, the approach enables the creation of smaller crystallites in the perovskite films as uncontrolled crystallite growth affects the efficiency and durability of cells.

The technique aims to avoid the efficiency loss caused by humidity linked to the interactions of ambient water and oxygen with the perovskite precursors and substrate used during cell production.

Italian research team develops graphene-enhanced tandem perovskite cell with 26.3% efficiency

Italian researchers from two Italian institutions claim to have developed a two-terminal tandem perovskite-silicon solar cell with a conversion efficiency 26.3%.

Structure of graphene-enhanced PSC image

The researchers added graphene to the titanium dioxide electron selective layer used in a perovskite solar cell to increase chemical stability. The two-terminal cell was made by stacking two sub-cells which were fabricated and optimized separately. The new device blends the advantages of thin-film perovskite and silicon-based heterojunction cells, according to its developers.

KAIST team produces perovskites at reduced temperatures to improve efficiency of single-crystal PSCs

KAIST researchers have designed a method to make perovskite crystals at lower temperatures, that could lead the way towards lower-cost solar cells by eliminating defects that reduce efficiency.

Most current work on perovskite solar cells focuses on polycrystalline versions, where the efficiency record is 25%, say Omar Mohammed and Osman Bakr, materials scientists at King Abdullah University of Science and Technology. But polycrystalline films are only a few hundred nm thick, whereas single crystals can be grown to approximately 20 µm. The thicker films can absorb more light so single-crystal solar cells could prove to be superior. The problem is that so far, single-crystal lead perovskite solar cells don’t reach 20% efficiency.

International consortium announces 25% efficiency for perovskite CIGS solar cell

Scientists from Hasselt University, imec, VITO, EnergyVille and international partners within the PERCISTAND consortium have announced that they achieved an energy efficiency of 25% with a thin-film solar cell.

Bart Vermang, coordinator within the PERCISTAND consortium, describes the development of thin-film solar cells as ‘Pioneering’. The consortium, which partly consists of the collaborations within EnergyVille and Solliance, has succeeded in achieving a record energy efficiency with thin film solar cells. ‘We’ve achieved an energy efficiency of 25 percent for the first time, which is just as much energy as a traditional solar cell can generate on a day-to-day basis. And we haven’t yet reached the upper limit of our thin-film solar cells.’

Peppermint oil and walnut aroma to enable HT material that prevents lead leakage in perovskite solar cells

Researchers at the Pohang University of Science & Technology (POSTECH) have developed eco-friendly-solvent processable hole transport polymers by using peppermint oil and walnut aroma food additives and the polymer can prevent lead leakage.

The POSTECH research team consisted of Prof. Taiho Park and Junwoo Lee, that developed Alkoxy-PTEG - hole transport polymers that could be dissolved in peppermint oil, by applying ethylene glycol side chains when producing perovskite solar cells. Also, the team confirmed that this polymer captured leaking lead in aging perovskite solar cells.