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.

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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.

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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

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 design novel passivation approach to achieve perovskite solar cells with efficiency of over 23%

Researchers from The Australian National University, Flinders University, University of New South Wales and The University of Sydney have developed a perovskite solar cell with a novel passivation process based on the use of guanidinium (Gua) and octylammonium (Oa) spacer cations.

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The device structure and the surface incorporation of GuaBr, OABr, and their mixture. Image from RRL Solar

 A schematic showing the device structure and the surface incorporation of GuaBr, OABr, and their mixture. Image from RL Solar

The team claims that guanidinium salts can improve the performance of the perovskite film, as guanidinium ions are capable of penetrating into the bulk of the perovskite material and localizing at the grain boundaries (GBs).

Read the full story Posted: Jun 13,2022

DOE awards funding for 3 perovskite-related PV projects

The U.S. Department of Energy (DoE) has selected 19 projects for which to grant a total funding of $6 million, to pursue innovative, targeted, early-stage ideas in solar energy research and development. The projects were selected through the Solar Energy Technologies Office (SETO) Small Innovative Projects in Solar (SIPS) 2022 Funding Program.

Projects were awarded in two solar energy research areas: PV and concentrating solar-thermal power (see CSP winners here). PV projects will improve power conversion efficiency, energy output, reuse and recycling processes, service lifetime, and manufacturability of PV technologies. Of the 19 selected project, 3 were perovskite-related.

Read the full story Posted: Jun 11,2022

Hyundai Motor to work with UNIST researchers to develop perovskite solar cell for vehicle solar roof

Recent reports claim that South Korea's Hyundai auto group has teamed up with a research team at Ulsan National Institute of Science and Technology (UNIST) to develop new perovskite solar cells that can charge vehicles while they are under the sun. 

Hyundai Motor already released solar roofs with silicon solar panels, but their acceptance has been slow without improvements in weight and efficiency, as silicon solar cells are quite heavy and have technical limitations in improving efficiency. In a recent ceremony, the Ulsan National Institute of Science and Technology (UNIST) opened a joint laboratory with Hyundai to develop high-efficiency, large-area perovskite-silicon tandem cells and apply them to solar roofs. The joint laboratory will operate for three years until May 2025.

Read the full story Posted: Jun 10,2022

Researchers improve tech for efficient and stable perovskite PV for solar windows

Australian researchers from Monash University and CSIRO have reported a way to improve the energy efficiency and longevity of solar integrated glass, while also allowing more natural light to pass through it. The researchers have demonstrated power conversion efficiencies of 15.5% and 4.1% for different types of prototype semi-transparent solar cells, with visible transmittance of 20.7% and 52.4% respectively.

This work builds on achievements made two years ago, when the same team created a solar window prototype that let through 10% of visible light and achieved 17% power conversion efficiency. According to the team, the upper power conversion efficiency achieved in the newer prototype is slightly lower than was achieved back in 2020 – 15.5% compared to 17% – but the pass-through of visible light is “significantly greater”, increasing their viability for real-world applications.

Read the full story Posted: Jun 06,2022

New technique could help upscale the production of perovskite solar cells

Researchers from the City University of Hong Kong and the Southern University of Science and Technology in Shenzhen, China, have shown that a self-assembled monolayer can facilitate the formation of a large-area perovskite film using a blade-coating process, thus promote the upscaling of perovskite photovoltaic technology.

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Researchers develop new technique to upscale the production of perovskite solar cells image

Researchers build perovskite solar cells with layers of material deposited on an underlying substrate. In adapting the high-speed blade-coating method for perovskite thin-film deposition, the researchers realized that the surface properties of the substrate are critical for large-area coating and perovskite growth. The current process leaves voids at the buried interface of the perovskite film that is detrimental to the device performance. “To solve this problem, we have screened various hole-transporting materials and found that self-assembled monolayers are a class of promising materials for the upscaling of perovskite devices,” said Alex Jen, a professor at City University of Hong Kong.

Read the full story Posted: Jun 01,2022

Researchers use ferrocene interlayer for efficient and stable perovskite solar cells

Scientists from Imperial College London, the University of Surrey, the University of Nottingham, research institute UCL, Switzerland-based Fluxim and London South Bank University have designed a perovskite solar cell that integrates a ferrocene co-mediator interlayer at the interface between the spiro-OMeTAD hole transport layer (HTL) and the active perovskite material.

The team noted that the migration of lithium is critical in the degradation of spiro-OMeTAD-based devices, which is accelerated at higher temperatures, leading to the rapid degradation of the perovskite. The scientists described ferrocene as a sandwich structured material that is highly stable and can be used as a low-cost transition metal complex.

Read the full story Posted: May 29,2022

Researchers achieve 17.5% efficiency with terbium-doped perovskite solar cell

Researchers from Chonnam National University in South Korea, Shivaji University in India, the Belgian research institute KU Leuven and Cardiff University in the UK have built an all-inorganic perovskite solar cell with a terbium doped solar absorber, which reportedly increases thermal stability.

The scientists developed a low-cost and simple hot-air method and also used terbium doping and quantum passivation techniques to stabilize the perovskite phase in the ambient conditions - with all processes carried out in ambient conditions.

Read the full story Posted: May 28,2022

Researchers find way to mitigate both performance losses and intrinsic degradation processes in perovskite solar cells

Researchers from the UK's University of Cambridge and Diamond Light Source, working with scientists from Japan's Okinawa Institute of Science and Technology (OIST), have found that the defects which limit the efficiency of perovskites are also responsible for structural changes in the material that lead to degradation.

In their work, the researchers used a combination of techniques to mimic the process of aging under sunlight and observe changes in the materials at the nanoscale, helping them gain new insights into the materials. Their findings could accelerate the development of long-lasting, commercially available perovskite photovoltaics.

Read the full story Posted: May 25,2022

Researchers use nitrogen-doped carbon nanodots to improve the stability and power conversion efficiency of perovskite solar cells

Researchers from the University of the Basque, University of Trieste and the Basque Research and Technology Alliance (BRTA) have managed to improve the stability and power conversion efficiency of a solar cell based on methylammonium (MA)-formamidinium (FA) lead halide perovskite, by using graphitic and amorphous nitrogen-doped carbon dots (g-N-CDs) as an additive.

In their study, the team set out to examine the influence of carbon dot additives on he efficiency and stability of PSCs. They found that the stability of the g-N-CDs-containing cells was improved. The long-term evaluation of the performances of the cells showed improvement of the power conversion efficiency of the g-N-CDs-containing cells over time, up to 109% of the initial efficiency after 40 days while the reference performance without CDs dropped to 86%.

Read the full story Posted: May 25,2022

Saule Technologies and Columbus Energy begin strategic cooperation with Google Cloud on innovations using perovskite solar cells

Saule Technologies and Columbus Energy have partnered with Google Cloud, signing a strategic cooperation agreement to develop new products using perovskite solar cells and solutions in the field of distributed energy and IoT (Internet of Things). Google Cloud will also become a strategic partner of both companies, providing cloud computing services and technologies.

The concept behind IoT is to connect a variety of often small and highly-specialized electronic devices in a network so that they can generate and send information to each other. However, such devices require power and this has greatly limited their potential applications to date. The perovskite solar cells developed by Saule Technologies are not only lightweight, thin and flexible, but they are also able to perform well even in artificial light. These unique advantages make Saule Technologies cells "the perfect energy source for all kinds of IoT devices in virtually all conditions, regardless of power grid availability", according to the Company's statement.

Read the full story Posted: May 24,2022