Perovskite-Info: the perovskite experts

Researchers from Karlsruhe Institute of Technology have developed a new fabrication technique based on inkjet printing that could enable fast, efficient and scalable production of perovskite solar cells.

“Developing a well-working inkjet printing process for the fabrication of perovskite solar cells could not only enable low-cost mass production, but would also offer to easily modify the printed design based on digital image files opening up the market for individually customized solar cells,” said Helge Eggers, doctoral student in the research group of Dr. Ulrich W. Paetzold from Karlsruhe Institute of Technology.

A Pohang University of Science & Technology (POSTECH) research team has designed a halide perovskite material for next-generation memory devices. Characteristics like low-operating voltage and high-performance resistive switching memory could mean great commercialization potential.

As rapid distribution and transmission of high-quality contents are growing rapidly, it is critical to develop reliable and stable semiconductor memories. To this end, the POSTECH research team succeeded in designing an optimal halide perovskite material (CsPb₂Br₅) that can be applied to a ReRAM device by applying first-principles calculation based on quantum mechanics.

The performance of photodetectors based on perovskite polycrystalline thin films is still considered to be at a distance from expected values. One reason is that the carrier transport at the interface is easily affected by grain boundaries and grain defects. Many research groups have tried to combine perovskite polycrystalline thin films with high-mobility, two-dimensional materials to improve device performance, and have achieved promising results, but the negative effects of perovskite polycrystalline grain boundaries still remain.

To solve this problem, a team led by Assoc. Prof. Yu Weili from Changchun Institute of Optics, Fine Mechanics and Physics (CIOMP) of the Chinese Academy of Sciences, and Prof. GUO Chunlei from the University of Rochester synthesized a low-surface-defect-density CH₃NH₃PbBr₃ microplate through the inverse temperature crystallization strategy. They prepared an effective vertical structure photodetector combining a high-quality perovskite single crystal with monolayer graphene with high carrier mobility.

A recent study reported the highest efficiency ever recorded for full roll-to-roll printed perovskite solar cells (PSCs), marking a significant step on the way to cheaper and more efficient ways of generating solar energy.

The team at Swansea University's SPECIFIC Innovation and Knowledge Center, led by Trystan Watson, reported using a roll-to-roll fabrication method for four layers of slot-die coated PSCs. The PSCs gave the stable power output of 12.2 percent - the highest efficiency recorded for four layers of roll-to-roll printed PSCs to date.

Researchers at Cambridge’s Department of Materials Science and Metallurgy, working with Imperial College London and the Solar Energy Research Institute of Singapore, have developed a method to print ultrathin coatings on perovskite-based solar cells, allowing them to work in tandem with silicon solar cells to boost efficiencies.

Solar cells work by absorbing sunlight to produce clean electricity. But photovoltaics can absorb only a fraction of the solar spectrum, which limits their efficiencies. The typical efficiency of a solar panel is only 18-20%.

Researchers in the Cava Group at the Princeton University Department of Chemistry have lifted the mystery surrounding the reasons for instability in the inorganic perovskite cesium lead iodide (CsPbI₃), known for its potential in creating highly efficient solar cells.

Using single crystal X-ray diffraction performed at Princeton University and X-ray pair distribution function measurements performed at the Brookhaven National Laboratory, the Princeton researchers detected that the source of thermodynamic instability in the halide perovskite cesium lead iodide (CsPbI₃) is the inorganic cesium atom and its “rattling” behavior within the crystal structure.

An international research team, led by Stefan Weber from the Max Planck Institute for Polymer Research in Mainz, has found microscopic structures in perovskite crystals that can guide the charge transport in the solar cell.

Clever alignment of these electron highways could make perovskite solar cells more efficient. When solar cells convert sunlight into electricity, the electrons of the material inside the cell absorb the energy of the light. The electrons excited by the sunlight are collected by special contacts on the top and bottom of the cell. However, if the electrons remain in the material for too long, they can lose their energy again. To minimize losses, they should therefore reach the contacts as quickly as possible. Microscopically small structures in the perovskites - so-called ferroelastic twin domains - could be helpful in this respect: They can influence how fast the electrons move.