January 2020

A new paper claims that scientists have reached a consensus on the procedures for the testing of perovskite cells, which they say will lead to better reproducibility and comparability of data produced by different laboratories, and ultimately a better understanding of the degradation pathways affecting perovskite solar cells, and the most effective ways to mitigate them.

Perovskites still have a way to go to convince the PV industry of their potential for long term durability. The class of materials' sensitivity to moisture and other conditions they would be sure to encounter in the field has continued to be a stumbling block.

The groups of Steve Albrecht and Bernd Stannowski at HZB have reached a record efficiency of 29.15% of its tandem solar cell made of perovskite and silicon.

The illustration shows the structure of the tandem solar cell: between the thin perovskite layer (black) and the silicon layer (blue) are functional intermediate layers. © Eike Köhnen/HZB

This value has been officially certified by the CalLab of the Fraunhofer Institute for Solar Energy Systems (ISE) and means that surpassing the 30% efficiency mark is now within reach.

University of California, Berkeley, scientists have created a blue light-emitting diode (LED) from halide perovskites, overcoming a major barrier to using these cheap, easy-to-make materials in electronic devices.

In the process, however, the researchers discovered a fundamental property of halide perovskites that may prove a barrier to their widespread use as solar cells and transistors. Alternatively, this unique property may open up a whole new world for perovskites far beyond that of today's standard semiconductors.

In what is said to be a "major milestone toward commercialization", Solliance partners TNO, imec and the Eindhoven University of Technology demonstrated encapsulated perovskite solar modules fabricated using industrial processes that withstand three established lifetime tests, i.e. the light soak test, the damp-heat test and the thermal cycling test. It is for the first time this milestone is passed with scaled perovskite solar modules prepared by research organizations.

The efficiency and versatility of perovskite solar modules has generated a lot of interest in this novel solar energy technology. However, concerns have been raised about the stability of perovskite solar modules since the early devices, reported a decade ago, were only stable for minutes. By passing three rigorous aging tests, Solliance and its industrial partners take a major step towards commercialization of this novel solar technology.

Japanese electronics giant Panasonic has reported the production of a lightweight 30_cmX30_cmperovskite solar module with an efficiency of 16.01%. The result was achieved in a research project by Japan's New Energy and Industrial Technology Development Organization.

The device has an area of 802cm² and thickness of 2mm. The manufacturer claims it improved module performance through an inkjet coating method and a reduction in weight by using thin glass substrates.

Researchers led by Prof. Antonio Abate at the Helmholtz-Zentrum Berlin have designed a study to investigate lead hazards relating to perovskite soar cells. They cooperated with plant scientists from the Fujian Agriculture and Forestry University, China, where the experiments were carried out, and with a group from the university of Naples, Italy.

Mint plants grown on control soil (left) and perovskite-contaminated soil (right). Credit: Nature

The plant experts prepared contaminated soil samples with different concentrations of lead from either perovskite solar cells or other lead sources and cultivated different plants. After a growth period, they analyzed the lead content in leaves and other parts of the plant. They found that lead from perovskite solar cells is 10 times more bioavailable than lead from other industrial sources.

Perovskite-Info is happy to announce the 2020 edition of The Perovskite Handbook. This book is a comprehensive guide to perovskite materials, applications and industry. Perovskites are an exciting class of materials that feature a myriad of exciting properties and are considered the future of solar cells, displays, sensors, LEDs and more. The handbook is now updated to January 2020 and lists recent developments and new companies, initiatives and research activities.

Reading this book, you'll learn all about:

• Different perovskite materials, their properties and structure
• How perovskites can be made, tuned and used
• What kinds of applications perovskites may be suitable for
• What the obstacles on the way to a perovskite revolution are
• Perovskite solar cells, their merits and challenges
• The state of the perovskite market, potential and future

Researchers from the University of California San Diego, King Abdullah University of Science and Technology and the Air Force Research Laboratory have developed a technique that could enable the fabrication of longer-lasting and more efficient perovskite solar cells, photodetectors, and LEDs.

Strain-engineered, single crystal thin film of perovskite grown on a series of substrates with varying compositions and lattice sizes. Image Credit: David Baillot/UC San Diego Jacobs School of Engineering.

A major obstacle is the tendency of one of the best-performing perovskite crystals, α-formamidinium lead iodide (HC(NH₂)₂PbI₃, known as α-FAPbI₃), to assume a hexagonal structure at room temperature, in which photovoltaic devices are required to operate. This hexagonal structure cannot respond to most of the frequencies of light in solar radiation, and is hence not useful for solar applications as it could be. The team therefore set out to stabilize the structure of α-FAPbI3, using a simple but useful approach known as strain engineering, which has been used to tune the electronic properties of semiconductors.

In September 2019, a research team led by Prof. Steve Albrecht from the HZB (in close collaboration with Kaunas University of Technology in Lithuania) announced a tandem solar cell with certified efficiency of 23.26% that combines the semiconducting materials perovskite and CIGS. Now, the team shares further details on these cells and states that an unnamed Japanese manufacturer has acquired the rights to produce them.

The scientists said the self-assembling material used for the cell is made of molecules based on carbazole head groups with phosphonic acid anchoring groups, and consists of 1-2nm of self-assembled monolayers deposited on the surface of the perovskite by dipping it into a diluted solution.

Researchers at EPFL in Switzerland have reported on the use of Flash Infrared Annealing (FIRA) to rapidly produce efficient, stable perovskite solar cells.

FIRA shares many characteristics with thermal annealing techniques already used to grow pure crystal phases for the semiconductor industry. It works by using a short IR pulse to rapidly nucleate a perovskite film from a precursor solution, without the need for a high-temperature scaffold. The high speed and relatively low processing temperatures mean that FIRA is compatible with large-area deposition techniques, like roll-to-roll processing. For PSCs, it could offer a practical route to scaling-up production.