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.
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 synergetic substrate and additive engineering to achieve over 30%-efficient perovskite-Si tandem solar cells
Researchers from EPFL, CSEM and Empa have demonstrated a cell design combining additive and substrate engineering that yields consistently high power conversion efficiencies and discussed various design aspects that are important for reproducibility and performance.
The team presented two key developments with a synergetic effect that boost the PCEs of tandem devices with front-side flat Si wafers—the use of 2,3,4,5,6-pentafluorobenzylphosphonic acid (pFBPA) in the perovskite precursor ink that suppresses recombination near the perovskite/C60 interface and the use of SiO2 nanoparticles under the perovskite film that suppress the enhanced number of pinholes and shunts introduced by pFBPA, while also allowing reliable use of Me-4PACz as a hole transport layer.
Researchers use DBM additive engineering for efficient and stable carbon-based CsPbI2Br perovskite solar cells
Researchers at China's Shanghai University of Electric Power have used dibenzoylmethane (DBM) as a precursor additive introduced in order to regulate the crystallization of CsPbI2Br perovskite while passivating its associated defects.
Inorganic CsPbI2Br perovskite solar cells (PSCs) have attracted massive interest but the tendency towards unruly crystallization and poor film quality of inorganic CsPbI2Br perovskites are major factors limiting their performance improvement. In their recent work, the scientists used DBM additive engineering for efficient and stable carbon-based CsPbI2Br PSCs.
Researchers improve performance of all-inorganic perovskite solar cells through bandgap grading and material design
Researchers from India's Chiktara University have reported improved stability and performance of organic-inorganic perovskite solar cells by applying a strategy called bandgap grading.
The method is based on enabling the cell perovskite absorber to collect a wider range of light photons by modifying its thickness and characteristics. The team explains that its recent study demonstrates the effectiveness of both linear and parabolic bandgap grading strategies in optimizing light absorption and boosting performance, showing its potential.
SOLRA-PV demonstrates its indoor perovskite solar PV
Israel-based SOLRA-PV showcases its cutting-edge indoor perovskite solar panel technology in action by successfully powering an entire IoT device setup. The system comprises an indoor panel, an environmental sensor, Bluetooth, and power management.
As you can see in the video, the prototype device performs a measurement every 10 minutes and transmits it to the smartphone. Utilizing SOLRA-PV's panels effectively captures indoor light for power generation, thus paving the way for the development of battery-free devices. The Company states that under indoor light conditions of 1000 lux, the panel produces 0.5 mW of power.
Researchers expand previous development for wider applications in perovskite solar cells
Researchers from King Abdullah University of Science and Technology (KAUST), Kaunas University of Technology and Helmholtz-Zentrum Berlin (HZB) recently improved on a previous development of record-breaking solar cells a few years ago, by expanding their invention: the self-assembled monolayers (SAMs) can now be applied not only in inverted but also in regular structure perovskite solar cells.
Self-assembling molecules arrange themselves into a single-molecule-thick layer and in this case, they act as an electron-transporting layer in solar cells.
Japan sees need for sharp increase in power output by 2050, counts on perovskite solar cells to assist
It was reported that the Japanese government estimates the need for electricity output to rise 35% to 50% by 2050 due to growing demand from semiconductor plants and data centers backing artificial intelligence (AI).
It was mentioned that the country is counting on perovskite solar cells, floating offshore wind farms, restarts of nuclear power plants and the introduction of next-generation reactors to meet the demand.
Researchers develop efficient inkjet-printed perovskite solar cells
Researchers from Germany's Karlsruhe Institute of Technology (KIT) have developed a scalable two-step evaporation and inkjet process for perovskite thin-film solar cells. The new technique is said to enable champion cells with the same efficiencies as those made with the spin coating process.
The process is described as a scalable and reliable technique for high-quality perovskite deposition, which combines the use of an evaporated lead iodide layer with inkjet-printed organic perovskite precursor materials. It is also said to exhibit high reproducibility and potential for conformal growth on textured silicon, and that provide films that are free of drying effects and toxic solvents.
Renshine Solar announces large perovskite modules with 18.4% efficiency
China-based RenShine Solar has announced that following the completion and commissioning of its 150MW perovskite photovoltaic module project in January, 2024, the Company's 1.2*0.6㎡ commercial size single-junction perovskite was certified by the China Institute of Metrology. The steady-state efficiency of the entire module area reportedly reaches 18.4%.
The production line aims to achieve mass production of 1.2m*0.6m perovskite modules with 20% efficiency by mid-2024. It plans to develop gigawatt-scale production lines to further expand its capacity.
Researchers use dopant-additive synergism to develop perovskite solar module with efficiency of 23.3%
Researchers from EPFL, Soochow University, Chinese Academy of Sciences, Lomonosov Moscow State University, Luxembourg Institute of Science and Technology (LIST), Julius Maximilian University of Würzburg, Toin University of Yokohama, Southern University of Science and Technology, Xi’an Jiaotong University, North China Electric Power University and Toyota Motor Europe recently developed a solar panel relying on EPFL's record-breaking 25.32%-efficient 2D/3D perovskite solar cells unveiled in July 2023.
The group's research demonstrates a larger surface area of 27.22 cm2, achieving an impressive efficiency of 23.3%. In the paper, the scientists explain that the module's high efficiency was achieved thanks to a synergistic dopant-additive combination strategy aimed to improve the cell absorber's uniformity and crystallinity. They used, in particular, methylammonium chloride (MACl) as a dopant and a Lewis-basic ionic liquid known as 1,3-bis(cyanomethyl)imidazolium chloride ([Bcmim]Cl) as an additive.
Researchers design tin-germanium-based perovskite solar cell with potential efficiency of up to 31.49%
Researchers from Malaysia have simulated a mixed cation solar cell based on a perovskite absorber integrating tin (Sn) and germanium (Ge) as mixed B cations. By modulating the perovskite layer thickness, they achieved an efficiency ranging of 24.25% - 31.49%.
Perovskite absorbers using mixed cations have the potential to improve stability, light absorption, and charge carrier mobility. A cations are used to control the bandgap and stability of the perovskite material, while B cations are intended to modify electrical and optical characteristics of perovskites. The scientists explained that using both elements in the B cation via “compositional engineering ” enables to reduce their respective defects and increase the cell performance, when compared to using each of them separately. Furthermore, the Ge atoms can replace Sn atoms in the perovskite crystal structure.
