December 2021

2021 is soon over - and it was an interesting year, still dominated by the global pandemic, but also with an increased need and urgency to develop renewable energy technologies.

Here are the top 10 stories posted on Perovskite-Info in 2021, ranked by popularity (i.e. how many people read the story):

1. Oxford PV completes build-out of its Brandenburg factory (Jul 25)
2. TCL and Zhijing Nanotech collaborate on pQD solutions for LCD TVs (Jan 12)
3. Saule Technologies launches its production line of perovskite solar panels (May 23)
4. New comprehensive defect suppression strategy could yield high-efficiency LEDs (Jan 8)
5. Saule Technologies announces plan to go public (Apr 20)
6. GCL raises over $15 million for 100 MW perovskite solar panel production line (Mar 11)
7. When will perovskite solar panels hit the market? (Sep 15)
8. Researchers reach 25.6% conversion efficiency using a novel engineering concept (Apr 7)
9. Researchers analyze importance and feasibility of recycling perovskite solar cells (Jun 26)
10. Flexible semi-transparent tandem perovskite/CIGS solar cell with 26.5% efficiency (Feb 11)

A consortium led by Hanwha Q Cells, a leading manufacturer of photovoltaic solar cells in South Korea, has been selected for a three-year state project to develop and commercialize perovskite crystalline silicon solar cells with high durability and high efficiency by using tandem cell technology that builds perovskite on top of silicon solar cells.

Tandem solar cells can be individual cells or connected in series, which are simpler to fabricate but the current is the same through each cell. Hanwha Q Cells said the consortium involving three private companies, two research bodies and three universities has signed an agreement with the state-run Korea Institute of Energy Technology Evaluation and Planning (KETEP) to develop module process technologies.

Researchers from the Diamond Light Source and the electron Physical Science Imaging Centre (ePSIC), Imperial College London, Yonsei University, Wageningen University and Research, and the University of Leeds have developed a method to stabilize perovskites without compromising their performance.

The researchers used an organic molecule as a 'template' to guide perovskite films into the desired phase as they form.

Researchers from the Hefei Institutes of Physical Science (HFIPS) under the Chinese Academy of Sciences (CAS), University of Science and Technology of China, North Minzu University, Hefei University of Technology, Greece's Institute of Nanoscience and Nanotechnology (INN) and Australia's Greatcell Energy have developed perovskite solar cells with a self-recovery capability and high stability in humid environment by introducing polymer called polyvinylpyrrolidone.

The team has shown that polyvinylpyrrolidone, a long chain insulating polymer, could form hydrogen bonds with ions in the cells and also prevent moisture in the air from invading perovskite materials. The hydrogen-bonding-initiated self-healing repairs the decayed perovskite solar cell back to the original state, continue to work, and alleviate long-term cell instability.

Researchers from Germany's Forschungszentrum Jülich have developed a planar perovskite solar cell that reportedly reached over 1,400'hours of operational stability at elevated temperatures. The 20.9% efficient device was built without the ionic dopants or metal oxide nanoparticles that are commonly used to contact the cell, as these can be subject to secondary reactions at higher temperatures.

The scientists tested many different perovskite mixtures before choosing the perovskite material for the cell, giving great focus to their thermal stability, using a self-constructed, high-throughput screening platform.

Researchers from Innovation Lab HySPRINT at Helmholtz-Zentrum Berlin (HZB) and Humboldt Universität zu Berlin (HU) have used an advanced inkjet printing technique to produce a large range of photodetector devices based on a hybrid perovskite semiconductor.

By mixing three inks, the researchers were able to precisely tune the semiconductor properties during the printing process. Inkjet printing is already an established fabrication method, allowing fast and cheap solution processing. Extending the inkjet capabilities from large area coating towards combinatorial material synthesis could open the door to new possibilities for the fabrication of different kinds of electronic components in a single printing step.

Researchers from the Imperial College of London and University College London have demonstrated the photovoltaic-boosting effect that phosphorene nanoribbons (PNRs) can bring to perovskite solar cells. When applied in tandem with a perovskite solar cell, PNR-boosted cells achieved an efficiency above 21%, which the researchers defined as "on par with traditional silicon cell output levels".

PNRs, first produced in 2019, have many theoretical use cases, including enhancing batteries, biomedical sensors, and quantum computing. The PNRs directly aided the perovskite cells' hole mobility, improving overall efficiency.

Scientists at the National Renewable Energy Laboratory (NREL) have experimentally synthesized a nitride perovskite material that previously only existed in theory and measured its properties in collaboration with researchers at the Colorado School of Mines.

The new material could theoretically be used for microelectromechanical devices such as the ones used in telecommunications and other areas. Nitride perovskites have been computationally predicted to be stable, but not many have been synthesized, and their experimental properties remain largely unknown, the researchers explained in their new article.

Uppsala University spinoff Evolar has entered into a joint development project with an undisclosed Indian silicon solar module manufacturer to develop highly efficient perovskite/silicon tandem solar modules for the South Asian market.

'Evolar is developing a unique perovskite-based PV power booster technology that adds 25 percent power to conventional solar panels. Moreover, it is easy to integrate the perovskite thin film process into current production set-ups. We firmly believe that the combination of our perovskite-based technology and this manufacturing partnership, can play a key role in strengthening India's domestic solar module supply,' says Mats Ljunggren, CEO of Evolar AB.

Researchers from Queen Mary University of London, in collaboration with an international team of scientists, developed a new process for creating FAPbI₃.

One of the challenges with making FAPbI₃ is that the high temperatures (150°C) used can cause the crystals within the material to 'stretch', making them strained, which favors the yellow phase that isn't suitable for solar cells. While previous reports have used small amounts of additional chemicals/additives to help form FAPbI₃ under these conditions, it can be very hard to control the uniformity and amounts of these additives when making solar cells at a very large scale, and the long-term impact of including them is not yet known.