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).
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 at Argonne National Laboratory and Purdue University recently reported an effort to prevent perovskite solar cell degradation by tracking the movement of ions in perovskites.
The team used X-rays at the Advanced Photon Source and a custom-built characterization platform to reveal the way ions move within different perovskite crystals under ultraviolet radiation (UV). Scientists are interested in testing material stability under UV because it can significantly degrade solar cell performance, sometimes by more than 50%, after extended exposure.
Researchers at Ulsan National Institute of Science and Technology (UNIST) and Korea University have reported efficient, stable tin–lead halide perovskites (TLHP)-based PV and photoelectrochemical (PEC) devices containing a chemically protective cathode interlayer—amine-functionalized perylene diimide (PDINN). Their work may advance the commercialization of perovskite solar cells (PSCs) and have potential in green hydrogen production technology, ensuring long-term operation with high efficiency.
The presence of inherent ionic vacancies in tin-lead halide perovskites (TLHPs) has posed challenges, leading to accelerated device degradation through inward metal diffusion. To address this challenge, the research team developed the chemically protective cathode interlayer using amine-functionalized perylene diimide (PDINN). By leveraging its nucleophilic sites to form tridentate metal complexes, PDINN effectively extracts electrons and suppresses inward metal diffusion.
Researchers at the National University of Singapore (NUS), Chinese Academy of Sciences (CAS) and Avantama have developed a new interface using antimony doped tin oxides (ATOx), that creates a chemically stable interface between the cell layers that's more uniform, conducts electricity better, and is more transparent. This enabled reduced energy loss and improved cell efficiency - 25.7% (certified steady-state efficiency of 24.8%) for an area of 0.05 cm2, retained under maximum power point tracking over 500 h and 24.6% (certified steady-state efficiency of 24.0%) for an area of 1 cm2.
The team reported p-type antimony-doped tin oxides (ATOx) combined with a self-assembled monolayer molecule as an interlayer between the perovskite and hole-transporting layers (HTL) in inverted solar cells. The scientists said that ATOx increases the chemical stability of the interface; they showed that the redox reaction that commonly took place at the NiOx/perovskite interface is negligible at the ATOx/perovskite interface.
A consortium entitled "Scalable High-power Output and Low-Cost MAde-to-measure Tandem Solar Modules Enabling Specialized PV Applications" (SOLMATES) was selected for a Horizon Europe project.
The consortium consists of 3 RTOs including the HZB (Helmholtz Center in Berlin for Materials and Energy), Korea Institute of Energy Research (KIER) and TNO (Netherlands Organization for Applied Scientific Research), 5 universities including the Universität Innsbruck (project coordinator) and 6 SMEs. The SOLMATES initiative launched in December 2023 held an initial "kick-off" strategic research meeting on January 17-18, 2024, in Innsbruck, Austria.
Tin-based perovskite solar cells have attracted great research interest due to their excellent photovoltaic performance and environmentally friendly characteristics. However, TPSCs with ideal band gaps suffer from current losses, so new interface engineering strategies need to be developed to improve device performance. Researchers from Soochow University and Marmara University have reported high-performance tin-based perovskite solar cells (TPSCs) by constructing charge bridge paths.
The authors propose a method to construct charge transfer pathways through a simple post-growth treatment of 3-aminomethylbenzo[b]thiophene (3-AMBTh) on a perovskite film. The selective reaction of 3-AMBTh with exposed FA+ on the perovskite surface suppresses the formation of iodine vacancy defects, resulting in a reduction in trap density.
Researchers at the University of Sheffield have used silver (Ag) particles to form a SnO2:Ag nanoparticle composite transport layer, to improve the efficiency of perovskite solar cells.
SnO2 is known as one of the most efficient transport layers for perovskite solar cells. Adding the Ag nanoparticles increased the recombination rate (detrimental for device performance), and the charge carrier transfer and extraction was also enhanced (beneficial for device performance). In order to balance these opposing factors, the nanoparticle concentration was optimized at an intermediate concentration with a corresponding power conversion efficiency increase from 13.4 ± 0.7 % for reference solar cells without nanoparticles to 14.3 ± 0.3 % for those with nanoparticles.
Researchers at the University of Oxford, University of Toronto, Peking University, Kunming Medical University, Yunnan University, Chinese Academy of Sciences (CAS) and Academia Sinica have reported a chemically stable and multifunctional buffer layer material, ytterbium oxide (YbOx), for p-i-n perovskite solar cells (PSCs) by scalable thermal evaporation deposition.
This YbOx buffer has been used in p-i-n PSCs based on narrow-bandgap perovskite light-absorbing layers, with certified power conversion efficiencies exceeding 25%.
Canada-based Solaires Entreprises, developer of sustainable and scalable perovskite-based photovoltaic modules, has announced the launch of its first
Solaires deployed its fully functional pilot production line where it will be producing PV modules for customers. The pilot production line is located in Langford, BC, Canada.
TandemPV has raised $6 million, bringing its total to $27 million in venture capital and government support. The Company will use the funds to advance research and development and plans to build its first manufacturing facility.
The funding round was led by existing investor Planetary Technologies, an early-stage venture capital firm with deep expertise in climate tech. Other institutional investors participated, including new investor Uncorrelated Ventures, as well as executives from a variety of corporate sectors and such solar industry leaders as Tom Werner, former chairman, president and CEO of SunPower Corp.
Researchers at the University of Michigan and Arizona State University have examined bulky "defect pacifying" molecules as a way to increase the stability and overall lifespan of perovskite materials.
The team expects this novel way of preventing perovskite materials from degrading quickly could help enable solar cells estimated to be two to four times cheaper than today's thin-film solar panels.