Lead-free - Page 3

Researchers from University of North Carolina, North Carolina State University and Chinese Academy of Sciences have fabricated a mini perovskite solar module using a novel encapsulation technique based on the use of a self-healable, lead-adsorbing ionogel that prevents lead leakage and improves stability. The solar module has an area of 31.5cm² and has a reported efficiency of 22.9%.

Ionogel microstructure and lead adsorption mechanism. Image from article

The scientists explained that ionogel sealants were applied on the panel's front glass and between electrode and encapsulation glass, with the 100μm-thick inonogel being able to hold the shattered glass together even if the glass breaks. This is claimed to effectively suppress lead leakage from broken modules after hail test or compression by car wheels, and soaking in water for 45 days.

Unlike the narrow band emission based on free excitons in lead-perovskite nanocrystals (NCs), the low electronic dimensionality in lead-free double perovskite NCs can lead to self-trapped excitons (STEs), generating a broadband emission. To date, how the singlet/triplet STEs influence the photoluminescence properties and whether triplet STEs can generate efficient emission in double-perovskite NCs has been unclear.

A research team, led by Prof. Han Keli and Yang Bin from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences, recently synthesized double perovskite nanocrystals with bright photoluminescence emission based on triplet STEs.

A research group, led by Prof. Han Keli from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences (CAS), in collaboration with Prof. Miao Xiangyang's group from Shanxi Normal University, recently explored the colloidal synthesis of all-inorganic rare-earth-based double perovskite NCs with NIR emission, and revealed their exciton dynamics.

Previous studies mainly focused on the photoluminescence (PL) in the visible region, and those on the near-infrared (NIR) PL of lead-free perovskite NCs are rare.

Researchers from the Hong Kong University of Science and Technology (HKUST) have developed an inexpensive, lightweight, and lead-free photo-battery that has dual functions in harvesting solar energy and storing energy on a single device. This could enable users to charge a battery under the sun, without having to plug the device into the wall.

Despite the theoretical potential of such photo-batteries, in reality it seems that the poor interface between materials tends to create problems with charge transport, greatly reducing the efficiency in comparison to the simple system of a solar cell wired to an external battery. A team led by Prof. Jonathan Eugene Halpert, Assistant Professor from the Department of Chemistry at HKUST, has made advancements towards developing more efficient photo-batteries by using perovskites.

A research team, led by Prof. Di Dawei from the Zhejiang University College of Optical Science and Engineering, recently discovered that by using germanium (Ge), an environmentally friendly group-IV element, to partially substitute lead in the perovskite, it is possible to create highly luminescent perovskite materials and devices.

Schematic of the Ge'Pb PeLED device structure. Image from Nature Communications

To resolve the toxicity problem that arises from the use of lead, an effective method has been the use of tin (Sn) as a partial or full replacement of lead in the perovskite materials. This strategy has been particularly successful for perovskite solar cells. However, tin-based (including tin-lead) perovskite materials are generally very poor light emitters, causing unsatisfactory performance of tin-based perovskite light-emitting devices (LEDs).

A team of scientists at EPFL has come up with an efficient solution to the lead problem of perovskite solar cells, which involves using a transparent phosphate salt that does not block solar light and hence doesn't affect performance.

In case the solar panel fails, the phosphate salt immediately reacts with lead to produce a water-insoluble compound that cannot leach out to the soil, and which can be recycled.

Update: according to our latest information, this investment did not go through

Japan-based Green Science Alliance, which develops next-generation technologies for use in energy as well as in other fields, has invested in a Kyoto University start-up focused on perovskite solar cell research ' EneCoat Technologies.

EneCoat is working on more efficient and durable perovskite cells while also looking to develop lead-free perovskite cells.

Semiconductors that can exploit the omnipresent visible spectrum of light for different technological applications are highly sought after, but such semiconductors are often dexpensive and toxic. A group of scientists from Tokyo Institute of Technology and Kyushu University have collaborated to develop a low-cost and non-toxic narrow-gap semiconductor material with potential 'light-based' or photofunctional applications.

Tin-containing oxide semiconductors are cheaper than most semiconductor materials, but their photofunctional applications are constrained by a wide optical band gap. The team of scientists, led by Dr. Kazuhiko Maeda, Associate Professor at the Department of Chemistry, Tokyo Institute of Technology, developed a perovskite-based semiconductor material that is free of toxic lead and can absorb a wide range of visible light.

Scientists at The University of Manchester have developed a way to increase the environmental safety of perovskite solar cells by eliminating the lead release from broken cells. Using a bioinspired mineral called hydroxyapatite, a major constituent of human bone, they have created a 'failsafe' which captures the lead ions in an inorganic matrix. As a result, if cells are damaged, toxins are stored in an inert mineral, rather than released in the environment.

Unlike silicon solar cells, perovskite solar cells can be mass produced through roll-to-roll processing. Additionally, they are light and can be used in non-traditional settings such as windows and contoured roofs. However, up until now, application has been impacted by potential environmental risks. Perovskite solar cells contain lead, a cumulative toxin, and if the cells get damaged, lead ions may leak.

A research team, led by Professors Byungsoo Bae at KAIST and Taewoo Lee at Seoul National University, has developed a new perovskite light-emitting diode (PeLED) display material.

PeLED is a type of LED that uses perovskite as a light-emitting material. Currently, the production cost is lower than that of organic light emitting diodes (OLEDs) and quantum dot light emitting diodes (QLEDs), and it has the advantage of enabling sophisticated color realization.