Efficiency - Page 61

Researchers at the Centre for Hybrid and Organic Solar Energy (CHOSE) of the University of Rome 'Tor Vergata', along with researchers at the Italian Institute of Technology (IIT) and the University of Applied Sciences in Crete (TEI), have stated that they set a new record for conversion efficiency of a perovskite photovoltaic module with an area larger than 50 cm2.

The success was achieved as part of Graphene Flagship, the 1 billion euro European project that promotes graphene-based innovation in sectors like energy, electronics, technology and medicine. Perovskites photovoltaic modules' efficiency is usually demonstrated in the laboratory on cells less than 1 cm2 in size, whereas the new test was performed on modules with an area larger than 50 cm2. The electronic and chemical properties offered by graphene have made it possible to overcome the many difficulties related to the realization of large-area perovskite solar panels.

A collaboration between researchers at Stanford University and Arizona State University (ASU) resulted in a new perovskite-silicon tandem solar cell that converts sunlight to electricity with 23.6% efficiency. The team stated that work is being put into reaching 30% efficiency, and they believe that they "could be there within two years".

In the tandem cell created by Stanford and ASU, the top cell is composed of a perovskite compound and the bottom cell is made of silicon that is specifically tuned to capture infrared light. The perovskite and silicon cells boast efficiency of 15 and 21%, respectively. ASU provided the silicon bottom cell, while Stanford researchers fabricated the perovskite compound and subsequent cells. Throughout the yearlong collaboration, the ASU team also provided modeling support to design the tandem for maximum current generation, while the Stanford team characterized the tandem cells.

Researchers at the University of Toronto have developed a novel way to print perovskite solar cells easily and at a low cost. This breakthrough could lead to low-cost, printable perovskite solar panels capable of turning nearly any surface into a power generator.

Perovskite materials can be mixed into a liquid to form an ink, which allows them to be printed onto glass, plastic or other materials using a simple inkjet process. The common catch is, however, that in order to generate electricity, electrons excited by solar energy must be extracted from the crystals so they can flow through a circuit. That extraction happens in a special layer called the electron-selective layer, or ESL. The difficulty of manufacturing a good ESL has been one of the key challenges holding back the development of perovskite solar cell devices.

Researchers from Finland have shown that the perovskite KBNNO is able to turn sunlight, heat and movement into electricity - which could be useful for many energy sources and electronics, providing that work to make it more efficient is successful.

Various other minerals in the perovskite family have previously shown promise for generating different types of energy, but never at the same time like KBNNO. In this study, the researchers from the University of Oulu ran experiments using KBNNO that showed it was reasonably good at generating electricity from pressure and heat ' but not as good as other perovskites. However, they showed KBNNO could be modified to amplify these properties.

Researchers from Skoltech's Institute of Problems of Chemical Physics and Moscow State University have designed an inorganic perovskite solar batteries. The new devices reportedly exhibit very high efficiency in light conversion (10.5%).

The team said that: "our devices demonstrate tremendous efficiency and excellent repeatability of electric characteristics from sample to sample". "The obtained results demonstrate the high potential of inorganic complex halogenides which offers new opportunities for target design of photoactive materials for effective and stable perovskite solar batteries."

Researchers from the National Institute for Materials Science in Japan have developed new additives for the hole-transporting layer of perovskite solar cells, which aim to greatly improve cell stability. When placed in the dark, the cells did not show signs of deterioration even after 1,000 hours of testing, and under continuous light soaking, they lasted six times longer (in terms of the time it takes for their power conversion efficiencies to fall to 85% of their initial states) compared to cells treated with conventional additives.

The researchers hope that these results will accelerate the commercialization of perovskite solar cells. The research group directed its focus on a pyridine-based additive, TBP, which is used as an additive in a hole-transporting layer in the mesoporous-type cell structure. After conducting experiments and analyzing the results, the group found that chemical reactions occurring between TBP and perovskite materials were one of the major causes of stability deterioration.

Researchers at the EPFL, along with scientists from Luxembourg Institute of Science and Technology (LIST) have used microscopy with mass spectrometry to study the nanoscale elemental distribution of mixed perovskites, which is particularly relevant for photovoltaic reproducibility and efficiency.

Perovskite are usually deposited as thin films on a surface, and they self-organize into crystals capable of being used for efficient solar cells. Limited information is available about the self-organization of the material, or how the different elements distribute - all of which is vital for optimizing perovskite photovoltaics. This is why the team tried to reveal significant micro- and nanoscale elemental and structural properties in self-organizing mixed perovskite films.

Researchers at Australia's University of New South Wales announced the achievement of the highest efficiency rating with the largest perovskite solar cells to date. The 12.1% efficiency rating was for a 16 cm2 perovskite solar cell, the largest single perovskite photovoltaic cell certified with the highest energy conversion efficiency, and was independently confirmed by the international testing centre Newport Corp, in Bozeman, Montana. The new cell is at least 10 times bigger than the current certified high-efficiency perovskite solar cells on record.

The researchers also achieved an 18% efficiency rating on a 1.2 cm2 single perovskite cell, and an 11.5% for a 16 cm2 four-cell perovskite mini-module, both independently certified by Newport. The team estimated that it will be be able to "get to 24% within a year or so".

A team of researchers from the Israeli Bar-Ilan University and the Spanish Universitat Jaume I in Castello and Universidad de Granada have showed that the contact interface of the perovskite material in a perovskite-based solar cell is behind the drastic and random fluctuations that happen when the solar panels are tested.

The researchers have discovered a light-induced interfacial phenomena in hybrid perovskite solar cells between the n-type contact (TiO₂ or TiO₂/PCBM interlayer) and the perovskite absorber. By changing the n-type contact and measuring the solar cells under the same conditions, it was demonstrated that the light-induced phenomena originates at the interface.

Researchers at Australia National University (ANU) have developed a novel manufacturing technique for perovskite solar cells, that may boost their efficiency. The ANU team sees this as a breakthrough that 'significantly improved' the performance of perovskite solar cells, which can combine with conventional silicon solar cells to produce more efficient solar electricity.

The ANU team designed an approach that requires a small amount of the element indium to be added to one of the cell's layers, which is claimed to result in a 25% increase in its power output. With perovskite better at converting visible light into electricity, and silicon more efficient in the infrared part of the spectrum, a combination of both is a promising path going forward.