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.
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 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.
The latest perovskite solar news:
Oxford PV recently announced first close of Series D funding round, attracting major new investment and continued support from existing shareholders. The Company raised £31 Million - around $41 Million USD.
The round includes a major new investment from Goldwind, the leading provider of integrated renewable energy solutions in China, as well as investment from existing shareholders including Equinor and Legal & General Capital.
Researchers from Peking University have conducted an experiment which is said to have demonstrated large-area perovskite solar cells are more stable 35 km up than at ground level. The researchers tested the stability of the devices by sending them to an altitude of 35 km above the Inner Mongolia autonomous region of China using an high-altitude balloon.
The cells, which had an active area of 1 cm², were developed with a TiO2 mesoporous structure based on two mixed-cation perovskites, FA0.9Cs0.1PbI3 and FA0.81MA0.10Cs0.04PbI2.55Br0.40. “Moreover, different kinds of perovskite photoactive absorbers with and without UV filters were investigated”, the scientists said.
Korea East-West Power and Ulsan National Institute of Science and Technology (UNIST) have jointly launched a project to develop an ultra-high efficiency multi-junction solar cell using perovskite.
The company announced that researchers from the two organizations held the first meeting at its head office in Ulsan and discussed the technology of producing a standard cell (15.6×15.6 square centimeters)-sized large-scale solar panel by establishing a vacuum deposition semiconductor facility.
Researchers at the Energy Research Center of the Netherlands (ECN) have developed a bifacial tandem solar cell with a conversion efficiency of 30.2%. The new cell device – created with Dutch consortium Solliance – was made by applying a newly developed perovskite cell on top of an industrial bifacial crystalline silicon version.
This approach, according to the scientists, enables a significantly higher power conversion efficiency as one cell is optimized for high energy photons, and the other low energy particles. “The tandem device proposed here uses a four-terminal configuration, thus having separate circuits for the top and bottom cells that allow for dynamic fine tuning and optimization of the energy yield,” the creators of the cell wrote. The cell is also said to be better able to capture light on its front and rear sides by responding to the variability of incident light through its electronic design.
Researchers at the Japanese Kanazawa University aim to improve the performance of perovskite solar cells by using two kinds of titanium oxide - anatase and brookite.
The team claims to have reached a conversion efficiency of 16.82% in a perovskite cell by applying a brookite layer made of water-solute brookite nanoparticles on an anatase layer. This reportedly helps to improve the transport of electrons from the center of the cell to its electrodes, while also preventing charges from recombining at the border between the perovskite material and the electron transport layer. “Together, both these effects allow us to achieve higher solar cell efficiencies,” said the research coordinator, Md. Shahiduzzaman.