Tuning 2D perovskites may enable capturing solar energy more efficiently

By tuning the structure of a 2D perovskite solar material, researchers from KAUST and the Georgia Institute of Technology have shown they can prolong the lifetime of highly energetic hot carriers generated by light striking the material. The approach could offer a way to capture solar energy more efficiently.

"As an alternative to 3D hybrid perovskites, 2D hybrid perovskites have improved stability and moisture resistance," says Jun Yin, a member of Omar Mohammed's and Osman Bakr's research groups. However, hot carrier cooling in these materials has not been extensively studied, adds Partha Maity, a postdoctoral fellow on the KAUST team.

Korean research team develops CIGS-Perovskite hybrid flexible thin-film solar cells

A joint research team from the Gwangju Institute of Science and Technology (GIST) and the Korea Photonics Technology Institute has developed perovskite-enabled hybrid flexible copper indium gallium selenide (CIGS) thin-film solar cells that can convert all ultraviolet, visible and infrared sunlight into electric energy.

Current flexible CIGS thin-film solar cells are limited by a short wavelength band, from 300 to 390 nanometers, which is absorbed from the transparent electrodes at the top of the solar cell. They cannot convert short wavelength solar energy into electricity. The research team succeeded in developing CsPbBr3 perovskite high-efficiency fluorescents that light up visible light bands by absorbing the light in the ultraviolet region, and applied them to the top of the transparent photoelectric layer of CIGS solar cells.

Unique chalcogenide perovskites show promise for photovoltaics and LEDs

Scientists from the University at Buffalo have created thin films made from barium zirconium sulfide (BaZrS3), a category of materials known as chalcogenide perovskites, and confirmed that it has impressive electronic and optical properties previously predicted by theorists.

The films reportedly combine exceptionally strong light absorption with good charge transport — two qualities that make them ideal for applications such as photovoltaics and light-emitting diodes (LEDs).

Collaborative team examines surface defect-deactivation mechanism in perovskite solar cells

Researchers from the University of California, San Diego and UCLA, Soochow University and Westlake University in China, and Marmara University in Turkey, have examined the surface defect-deactivation mechanism in perovskite solar cells using molecules found in tea, coffee and chocolate.

Researchers unravel the surface defect-deactivation mechanism in perovskite solar cells using molecules found in tea, coffee and chocolate image

The collaborative team set out to delineate the molecular arrangements that constructively deactivate the surface defects in perovskite solar-cells. Highly-efficient metal-halide perovskite solar cells to date consist of polycrystalline perovskite film that often contains a high density of defects on the surface. These imperfections are the points for charge recombination, which is a major limiting factor in power conversion efficiency (PCE) and stability of perovskite solar cells. However, due to the ionic nature of the perovskite lattice, these defects can be passivated by surface treatment of perovskite with a small molecule.

NUS Team demonstrates large area, flexible perovskite IR LEDs

Researchers at the National University of Singapore (NUS) have developed highly efficient, large-area and flexible perovskite-based near-infrared LEDs for new wearable device technologies.

High-efficiency PeLEDs by NUS image

The team, led by Tan Zhi Kuang from the Department of Chemistry and the Solar Energy Research Institute of Singapore (SERIS), has developed high-efficiency near-infrared LEDs which can cover an area of 900 mm2 using low-cost solution-processing methods. This is several orders of magnitude larger than the sizes achieved in previous reports, and opens up a range of new applications.