December 2015

Researchers at MIT have developed a simple procedure for making a perovskite solar cells using lead recovered from lead-acid car batteries, a method that could have both environmental and health benefits.

They first drained and disassembled the batteries, then extracted the lead from the anode and lead dioxide from the cathode; the latter was then processed to make lead oxide. Both were then dissolved in acids and mixed with aqueous potassium iodide. The lead iodide precipitate is dried to a powder, dissolved in solvent and spin coated onto a substrate. The lead iodide precipitate was dried to a powder, dissolved in solvent and spin coated onto a substrate. The lead iodide film then went through a reaction with organic halide to form perovskite.

Researchers at TU Wien (Vienna) explored the long-standing question of how water molecules behave when they attach to a perovskite surface, by using scanning tunneling microscopes and computer simulations.

While usually only the outermost atoms at the surface are of importance, in perovskites the deeper layers are important, too. The team studied strontium ruthenate - a typical perovskite material that has a crystalline structure containing oxygen, strontium and ruthenium. When the crystal is broken apart, the outermost layer consists of only strontium and oxygen atoms; the ruthenium is located underneath, surrounded by oxygen atoms. A water molecule that lands on this surface splits into two parts: A hydrogen atom is stripped off the molecule and attaches to an oxygen atom on the crystal's surface. This process is known as dissociation. However, although they are physically separated, the pieces continue to interact through a weak "hydrogen bond".

Researchers at Pennsylvania State University have developed a transparent and electrically conductive material that could make large screen displays, smart windows, touch screens and solar cells more affordable and efficient. The material has the potential to replace indium tin oxide (ITO), the transparent conductor that is currently used for more than 90% of the display market but is expensive, scarce and brittle.

Along with display technologies, the researchers will investigate the new materials with a type of solar cell that uses organic perovskite materials. The team has reported a design strategy using 10 nm-thick films of an unusual class of materials called correlated metals. In most conventional metals, such as copper, gold, aluminum or silver, electrons flow like a gas. In correlated metals, such as strontium vanadate (a perovskite material) and calcium vanadate, they move more like a liquid. The electron flow produces high optical transparency along with high metal-like conductivity, the researchers said.

Researchers involved in the €10.6 million European research project called GRAFOL have reportedly demonstrated a cost-effective roll-to-roll production tool capable of making large sheets of graphene on an industrial scale, which could greatly contribute to flexible thin-film solar cells with transparent electrodes like perovskite PVs.

Researchers at the Japanese Kyoto University have designed a material called HND-Azulene, that can, when used as a hole-transporting material (HTM), increase the efficiency of perovskite solar cells by up to 20% when compared to the commonly used Spiro-OMeTAD. Such perovskite PV cells have exhibited a power conversion efficiency of over 16.5%, compared to an efficiency of 13.6% for cells using the current standard Spiro-OMeTAD.

The research team has designed and synthesized the HND-Azulene system with a sheet-shaped structure. Based on the evaluation and a comparison of the optoelectronic and electrochemical properties of HND-Azulene and Spiro-OMeTAD, the researchers were been able to determine the factors that are required for HTMs to act efficiently in perovskite solar cells. In line with these new molecular design principles, they believe that more sophisticated HTMs should be easily attainable.

Researchers at Pohang University in Korea are reportedly the first to develop a perovskite light emitting diode (PeLED) that could replace organic LED (OLED) and quantum dot LED (QDLED).

Organic/inorganic hybrid perovskite have much higher color-purity at a lower cost compared to organic emitters and inorganic QD emitters. However, LEDs based on perovskite had previously shown a limited luminous efficiency, mainly due to significant exciton (a complex of an electron and hole that can allow light emission when it is radiatively recombined) dissociation in perovskite layers.

In November 2015, Dyesol announced its plan to raise up to AUD 10 million (USD 7.25 million/EUR 6.8 million) by selling shares to shareholders and investors. Now, the company announce that it has successfully completed a capital raising of $8.1 million ($5.85 million USD).

Dyesol, the Australia-based renewable energy supplier and leader in Perovskite Solar Cell technology, announced that a research team at the Ecole Polytechnique Fédérale de Lausanne (EPFL) has established a remarkable efficiency for its Perovskite Solar Cells (PSC), with a conversion efficiency of 21.02%.

This conversion efficiency was certified at the laboratories of Newport Corporation in Bozeman, Montana USA. This new conversion efficiency eclipses the previous record of 20.1%.

The Australian Renewable Energy Agency (ARENA) will be providing about $650,000 to CSIRO for the development of guidelines for assessing the performance of the perovskite solar cells. This project will be carried out as part of an attempt to reduce the cost of renewable energy in the country by providing a funding boost to an innovative solar cell technology.

CSIRO is planning to establish new methods and guidelines applicable to perovskite solar cells, as international standards to measure solar PV cell performance are only applicable for silicon wafer cells. The new guidelines would be applied at the ARENA-supported PV Performance Laboratory in Newcastle, and the lab would help Australian researchers test perovskite samples in the country instead of conducting tests overseas, which will boost research and reduce the costs of the project.