Perovskite-Info: the perovskite experts

Researchers in Australia's University of Sydney have found a way to manipulate laser light at a fraction of the cost of current technology. The discovery could help drive down costs in industries as diverse as telecommunications, medical diagnostics and consumer optoelectronics.

The polarization of transmitted light is rotated by a crystal immersed in a magnetic field (top). The perovskite crystal (bottom right) rotates light very effectively, due to the atomic configuration of its crystal structure (bottom left)

The research team, led by Dr Girish Lakhwani from the University of Sydney Nano Institute and School of Chemistry, has used inexpensive perovskite crystals to make Faraday rotators. These manipulate light in a range of devices across industry and science by altering a fundamental property of light – its polarization. This gives scientists and engineers the ability to stabilize, block or steer light on demand.

University of Central Florida researchers are helping to close the gap separating human and machine minds, using a technology based on perovskite quantum dots. In a recent study, a UCF research team showed that by combining two promising nanomaterials into a new superstructure, they could create a nanoscale device that mimics the neural pathways of brain cells used for human vision.

"This is a baby step toward developing neuromorphic computers, which are computer processors that can simultaneously process and memorize information," said Jayan Thomas, an associate professor in UCF's NanoScience Technology Center and Department of Materials Science and Engineering. "This can reduce the processing time as well as the energy required for processing. At some time in the future, this invention may help to make robots that can think like humans."

Researchers at Spain’s Charles III University of Madrid claim to have significantly reduced optical losses in a monolithic, nano-structured perovskite silicon tandem solar cell by using a new design.

Such two-terminal tandem cell devices are said to offer high conversion efficiency, due to a large number of layers, but to also suffer significant optical losses because of the high number of interfaces.

Hunt Perovskite Technologies (HPT), a Texas-based perovskite applications developer, has reported a milestone in the development of a highly-durable perovskite technology for the manufacture of low-cost printed solar cells.

In December 2019, HPT demonstrated that its ink-based process was able to produce a perovskite solar cell that exceeded key benchmarks recognized by the solar cell manufacturing industry and exceeded the International Electrotechnical Commission (IEC) durability thresholds in temperature, humidity, white light and ultraviolet (UV) stress testing while reaching efficiency performance levels of 18%.

Researchers at Saudi Arabia’s King Abdullah University of Science and Technology (KAUST) claim to have improved the performance of solar cells based on inverted perovskites.

That type of cell has a device structure known as “p-i-n”, in which hole-selective contact p is at the bottom of intrinsic perovskite layer i with electron transport layer n at the top. Conventional halide perovskite cells have the same structure but reversed – a “n-i-p” layout. In n-i-p architecture, the solar cell is illuminated through the electron-transport layer (ETL) side; in the p-i-n structure, it is illuminated through the hole‐transport layer (HTL) surface.

A new study led by Brown University finds that cracks in brittle perovskite films can be easily healed with compression or mild heating, a good sign for the use of perovskites in next-generation solar cells.

A cracked perovskite film (left) can be fully healed (right) with some compression of a little heat. Credit: Padture Lab/Brown University

“The efficiency of perovskite solar cells has grown very quickly and now rivals silicon in laboratory cells,” said Nitin Padture, a professor in Brown’s School of Engineering and director of the Institute for Molecular and Nanoscale Innovation. “Everybody’s chasing high efficiency, which is important, but we also need to be thinking about things like long-term durability and mechanical reliability if we’re going to bring this solar cell technology to the market. That’s what this research was about.”

Researchers from three Japanese universities, led by Japan’s Kanazawa University, have developed a process based on inkjet printing they say could reduce the cost of perovskite solar cell production. The group fabricated small cells with efficiencies as high as 13.19%, a figure they claim is promising enough to offer the possibility of scaling up to commercial production.

Schematic illustration of (a) the OEI setup used to pattern the TiO2 CL on FTO glass substrates and (b) the device structure of OEI-TiO2 CL-based PSCs.

The team has developed a process for depositing a titanium dioxide electron transport layer (ETL) onto a perovskite. The group claim the method could be scaled up to cut costs for manufacturers moving towards commercial perovskite cell manufacturing.