Researchers stabilize perovskites in MOFs for use in LEDs

Researchers from the U.S. Department of Energy's (DoE) Argonne National Laboratory, Brookhaven National Laboratory, Los Alamos National Laboratory, SLAC National Accelerator Laboratory and Taiwan's Academia Sinica have reported the preparation of stable perovskite nanocrystals for LEDs.

Bright and stable LEDs made with perovskite nanocrystals imageLight-emitting diodes made from perovskite nanocrystals (green) embedded in a metal-organic framework. Image from Phys.org

Perovskite nanocrystals' unstable nature has so far hindered their potential to be used as LED materials. However, the research team managed to stabilize the nanocrystals in a porous structure called a metal-organic framework, or MOF for short. Based on earth-abundant materials and fabricated at room temperature, these LEDs could one day enable lower cost TVs and consumer electronics, as well as better gamma-ray imaging devices and even self-powered X-ray detectors with applications in medicine, security scanning and scientific research.

New data on double perovskite oxides could promote their use in fuel cells

A joint research team that includes researchers from the Institute of Solid State Chemistry and Mechanochemistry (the Ural Branch of the Russian Academy of Sciences), the Donostia International Physics Centre and the HSE Tikhonov Moscow Institute of Electronics and Mathematics has studied the characteristics of cubic double perovskite oxides.

To date, experimental measurements of the minerals' characteristics have not corresponded to the results of theoretical modeling. In this new work, the researchers set out to better understand this disparity. The data obtained could allow the improvement of low-temperature fuel cell technologies—one of the main alternatives to current sources of electricity.

Tandem perovskite-silicon solar cells power a highly efficient direct solar hydrogen generation system

Researchers from the Australian National University and the University of New South Wales (UNSW) recently used perovskite solar cells for the development of a novel technology for direct solar hydrogen generation (DSTH), claimed to achieve an impressive solar-to-hydrogen efficiency of around 20%.

In DSTH systems, the electricity generated by a PV unit is used to directly drive water-splitting redox reactions without the need for an electrolyzer or complex power infrastructure. Commercial viability, however, remains unattainable despite efficiencies close to 19%, due to the use of expensive semiconductors and noble-metal catalysts.

Korean researchers use virus to improve perovskite solar cells

Researchers from Sungkyunkwan University and Pusan National University recently succeeded in complementing an intrinsic defect of a perovskite solar cell’s absorber layer by adding a virus. The team showed that the efficiency of photoelectric transformation improved by using a virus rather than a chemical compound as solar cell thin film.

Solar cells based on perovskites as an absorber layer usually require the addition of a chemical compound due to intrinsic defects of perovskite crystal. Perovskite solar cells are limited as the process of adding chemical compounds is expensive and the purity of the generated material is low.

Perovskites enable simple and cheap neutron detector

Scientists at EPFL and their collaborators have developed a simple and low-cost perovskite-based device that detects neutrons. The perovskite materials used in the study are based on lead and bromine. Both contain single crystals of a compound called methylammonium lead tri-bromide.

The team first placed these crystals in the path of a neutron source. The neutrons, hitting the crystals, penetrate the nucleus of the atoms within the crystal, exciting them into a higher energy state. When they relax and decay, gamma rays are created. These gamma photons charge the perovskite, delivering a tiny current that can be estimated.

NREL and NASA test perovskite solar cells in space

Researchers at NREL, working with teams from NASA, are testing ways to bring production costs of solar cells down and transforming how PV technologies could work in space as well.

The latest test will evaluate the potential use of perovskite solar cells in space and assess the durability of materials used in those cells. NASA's Dr. Kaitlyn VanSant worked with Ahmad Kirmani, Joey Luther, Severin Habisreutinger, Rosie Bramante, Dave Ostrowski, Brian Wieliczka, and Bill Nemeth at NREL to prepare the perovskite cells and materials. Eight of these samples are scheduled to launch to the space station in August and another set of 25 samples will be launched in the spring of 2022. The samples, each of which are a square inch in size, are part of the Materials International Space Station Experiment (MISSE) program and will be fastened to the outside of the orbiting platform.

Researchers examine the potential of perovskites for next-gen LED-based data communications

Researchers from the University of Surrey and the University of Cambridge have examined how two semiconducting materials can satisfy the telecommunication industry's hunger for huge amounts of data at increasing speeds. Light-emitting diode (LED)-based communications techniques allow computing devices, including mobile phones, to communicate with one another by using infrared light. However, LED techniques are underused because in its current state LED transmits data at far slower speeds than other wireless technologies such as light-fidelity (Li-Fi).

The researchers from Surrey and Cambridge, along with partners from the University of Electronic Science and Technology of China, examine how organic semiconductors, colloidal quantum dots (CQDs) and metal halide perovskites, can be used in LED-based optical communications systems.