A group of chemists from Lithuania’s Kaunas University of Technology, the inventors of multiple groundbreaking inventions in the field of solar energy, proposed yet another approach to improve the stability and performance of perovskite solar components. They created a novel class of carbazole-based cross-linkable materials that are resistant to a variety of environmental factors, including the powerful solvents used in the manufacturing of solar cells. When used as hole carrying layers, the new materials discovered at Kaunas University of Technology (KTU) labs contributed to the inverted-architecture perovskite cells achieving 16.9% efficiency on the first try. It is projected to achieve greater efficiency after optimization.
Organic-inorganic hybrid perovskite solar cells have gained international interest as a viable alternative to traditional silicon-based solar technologies. They are less expensive, more adaptable, and have a higher power conversion efficiency. Scientists from all over the world are collaborating to address issues linked to enhancing the stability and other properties of perovskite solar components. These layered, next-generation solar cells can have one of two architectural structures: conventional (n-i-p) or inverted (p-i-n). The hole transporting materials are placed beneath the perovskite absorber layer in the latter.
“Although p-i-n cells have various advantages over conventional perovskite solar cells, they have significant drawbacks.” “The hole transporting compounds, for example, should be able to tolerate the strong polar solvents needed to build the light-absorbing perovskite layer, which is deposited above,” explains Professor Vytautas Getautis, chief researcher at KTU Faculty of Chemical Technology.
Polymers are frequently utilized as hole transportation materials in p-i-n architectures to solve this problem. However, due to solubility difficulties, forming a polymer layer is problematic; additionally, controlling the recurrence of reactions and synthesising the same structure is difficult. To address this issue, KTU researchers created a hole carrying layer of carbazole-based molecules that was then thermally polymerized in situ to achieve the cross-linking effect.
“A three-dimensional structure exists in the cross-linked polymer.” It is extremely resistant to a variety of impacts, including the harsh solvents used in the formation of a light-absorbing perovskite layer. “We employed multiple groups of molecules and created materials that, when used as a hole transporting layer, can boost the efficiency of an inverted perovskite solar cell by over 17%,” says the compounds’ synthesiser, PhD student arn Dakeviiit-Geguien.
The above-mentioned invention was featured on the cover of Chemical Communications, a journal produced by the Royal Society of Chemistry in the United Kingdom. And Unicorns, a Lithuanian design firm, designed the cover art.
Prof Getautis’ research group has created a slew of cutting-edge inventions targeted at increasing the efficiency of solar cells. Synthesized substances, for example, self-assemble into a molecule-thin layer that works as a hole carrying medium. The silicone-perovskite tandem solar made with the aforementioned ingredients achieved an efficiency of more than 29%. Prof Getautis believes that the latter tandem combination will soon become a commercially viable alternative to silicone-based solar cells — more efficient and less expensive.
“Our research intends to improve existing technologies for perovskite solar components, and we have obtained the best results in this field with the self-assembling-monolayer technology.” However, research is frequently developed in several directions, as we need to study the best ways to utilise solar energy,” adds Prof Getautis.
Although perovskite cells are newer than silicone-based solar technologies, some businesses have already commercialized devices based on perovskite technology. Flexible semi-transparent interior parts, wearing electronics to control wildlife populations, and diverse architectural solutions are among them. This is only the beginning.
Solar energy, according to Prof Getautis, has the greatest potential and is the least used of all renewables. However, thanks to recent research, this subject is growing at an exponential rate. Solar energy is expected to supply around half of the electricity used on Earth by 2050.
“Solar energy is completely green – it produces no pollution and requires little maintenance.” With current events and the energy problem in mind, an increasing number of people are interested in installing solar power plants in their houses or owning a stake of a solar farm. “It is the future of energy,” Prof Getautis believes.