January 2018

GreatCell Solar recently released a fascinating commercialization schedule for perovskite solar cells, as part of the Company's quarterly report. The schedule includes two timelines, one for glass and one for metal.

The glass section has 2018 as the year in which pilot lines will be set up, and 2019 as a production target. The metal section sees 2018 as a year focused in prototypes, 2019 on pilot lines and 2020 as a production timeline goal. This seems to be an encouraging aim and hopefully the actual progress will live up to expectations. We will certainly stay updated!

Researchers at the U.S. Department of Energy's National Renewable Energy Laboratory (NREL) have reported the development of an environmentally-stable perovskite solar cell that reportedly maintained 94% of its starting efficiency after 1,000 hours of continuous use under ambient conditions.

'During testing, we intentionally stress the cells somewhat harder than real-world applications in an effort to speed up the aging,' says an involved researcher at NREL. 'A solar cell in the field only operates when the sun is out, typically. In this case, even after 1,000 straight hours of testing the cell was able to generate power the whole time.'

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.

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.

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.

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.

Scientists at the Department of Energy's National Renewable Energy Laboratory (NREL) and at the University of Texas at Austin have conducted the first quantitative nanoscale photoconductivity imaging of two perovskite thin films with different power conversion efficiencies.

The team's microscopic analysis of perovskite solar cells reveals new insight into how the devices degrade'information necessary for improving their performance and moving the technology closer to commercialization.

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.

Saule Technologies, Poland-based developer of perovskite solar cells ink-jet printed on thin foil, has announced the signing of a cooperation agreement with Skanska's commercial development business unit in Central Eastern Europe.

The construction company will be the first to cover office buildings with semi-transparent perovskite solar cells on a commercial scale. Saule Technologies will be the technology provider. The initial implementation tests are planned for 2018 in Poland.

Researchers at the University of Groningen are working on a special type of solar cell that is made of organic-inorganic hybrid perovskites. The team has been focusing on a material in which hot electrons retain their high energy levels for much longer, which might make it possible to use more of their energy to obtain a higher voltage.

Most hybrid-perovskite solar cells contain lead, which is toxic. The research group recently published a paper describing 9% efficiency in a hybrid-perovskite solar cell containing tin instead of lead. "When we studied this material further, we observed something strange", the team said. The results showed that the hot electrons produced in the tin-based solar cells took about a thousand times longer than usual to dissipate their excess energy.