HZB team shows how holey perovskite films manage to maintain efficiency |
2018-01-17 07:01:33-05
Researchers from Germany’s research center Helmholtz Zentrum Berlin (HZB) have found the reason why holes in perovskite films produced through a spin coating technique and used in solar cells do not cause a reduction in the cells’ performance.
The team said that these holes, which are commonly responsible for leading to short circuits in the solar cell by the adjacent layers of the solar cell coming into contact, if produced through a spin coating technique, do not lead to significant short circuits between the front and back contact of the cell, and so do not negatively impact the cell’s performance.
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KAIST researchers use perovskites to maximize the lifespan of fuel cells |
2018-01-21 01:22:20-05
Fuel cells are a hoped to be a key future energy technology for achieving renewable energy sources that are eco-friendly and low-cost. In particular, solid oxide fuel cells composed of ceramic materials are gaining increasing amounts of attention for their ability to directly convert various forms of fuel such as biomass, LNG, and LPG to electric energy. Researchers at KAIST have relied on pervoskite materials to develop a new technique to improve the chemical stability of electrode materials that can extend their lifespan by employing minimal amounts of metals.
The core factor that determines the performance of solid oxide fuel cells is the cathode at which the reduction reaction of oxygen takes place. Conventionally, perovskite structure oxides (ABO3) are used in cathodes. However, despite the high performance of perovskite oxides at initial operation, performance degrades with time, limiting their long-term use. In particular, the condition of a high-temperature oxidation state required for cathode operation leads to a surface segregation phenomenon in which second phases such as strontium oxide (SrOx) accumulate on the surface of oxides, resulting in a decrease in electrode performance. The detailed mechanism of this phenomenon and a way to effectively inhibit it has not been suggested.
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Researchers use a micro-LED covered with perovskite QDs to achieve high-speed visible light communication |
2018-01-21 03:43:13-05
Researchers from Fudan University in China have developed a high-bandwidth white-light based system made from a blue gallium nitride (GaN) micro-LED with yellow-emitting perovskite quantum dots. This system could open the door to high-speed real-time visible light communication (VLC). The researchers used a 80 x 80 um blue-emitting micro-LED that has a modulation bandwidth of about 160 MHz and a peak emission wavelength of ~445 nm. The white-light system (following the perovskite QD conversion) achieves 85 Mhz - which means a maximum data rate of 300 Mbps.
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New gas-solid process could enhance the stability of perovskite solar cells |
2018-01-21 04:30:00-05
Scientists from China’s Liaocheng University and Hefei University of Technology have developed a new gas-solid process for the creation of perovskite thin films, which may lead to improved stability of perovskite-based solar cells.
The researchers noted that solvent based processes, the most common method for growing perovskite crystals on a substrate, often leads to defects and irregularities in the perovskite film, making it extremely sensitive to moisture and likely to decompose quickly under working conditions. So they suggested an alternative to using solvents, working on a gas-solid reaction process. Further details of the process itself were not provided, however the team states that crystals grown this way, and annealed at 120∘C for 30 minutes exhibited higher responsivity and detectivity than devices previously developed using solution based methods.
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Berkeley team creates perovskite material for smart photovoltaic windows |
2018-01-23 02:38:25-05
Lawrence Berkeley National Laboratory (Berkeley Lab) researchers have manipulated the chemical structure of perovskite so that the material turns from transparent to opaque when heated and also converts sunlight into electricity. This ability may lead to applications like windows that automatically tint on a sunny day to block the heat while also generating electricity, power-producing smart windows for buildings, cars and display screens, and more.
While the sunlight conversion efficiency of the material (an inorganic halide perovskite with added cesium, lead, iodine and bromine) is still low and the transition from transparent window to opaque solar cell requires heating the window to the boiling point of water, the team is already working on versions that work at lower temperatures and with higher conversion efficiency. The new material is reportedly able to retain its conversion efficiency after many cycles between transparent and a reddish tint.
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