A UNIST research team has developed an electrode that can significantly improve the stability of perovskite solar cells. UNIST announced that its research team developed 'flexible and transparent metal electrode-based perovskite solar cells with a graphene interlayer'.

The team suppressed interdiffusion and degradation using a graphene material with high impermeability, the team said. Team leader professor Hyesung Park commented that the research will greatly help not only solar cells but other perovskite-based flexible photoelectric devices such as LEDs and smart sensors.

An international team of scientists recently developed a new composite material based on perovskite nanocrystals to fabricate miniature light sources with improved performance.

Protection of perovskite nanocrystals within porous glass microspheres made it possible to increase their stability by almost 3 times. Moreover, the subsequent coating of these particles with polymers resulted in the fabrication of water-dispersible luminescent microspheres based on CsPbBr₃ nanocrystals. This method of fabrication is especially important for the implementation of perovskite nanocrystals in diverse biological applications.

Researchers at Northern Illinois University and the U.S. Department of Energy's (DOE) National Renewable Energy Laboratory (NREL) in Colorado have reported on a potential breakthrough in the development of hybrid perovskite solar cells.

Led by Tao Xu of NIU and Kai Zhu of NREL, the scientists have developed a technique to sequester the lead used to make perovskite solar cells and minimize potential toxic leakage by applying lead-absorbing films to the front and back of the solar cell.

Researchers in Australia's University of Sydney have found a way to manipulate laser light at a fraction of the cost of current technology. The discovery could help drive down costs in industries as diverse as telecommunications, medical diagnostics and consumer optoelectronics.

The polarization of transmitted light is rotated by a crystal immersed in a magnetic field (top). The perovskite crystal (bottom right) rotates light very effectively, due to the atomic configuration of its crystal structure (bottom left)

The research team, led by Dr Girish Lakhwani from the University of Sydney Nano Institute and School of Chemistry, has used inexpensive perovskite crystals to make Faraday rotators. These manipulate light in a range of devices across industry and science by altering a fundamental property of light ' its polarization. This gives scientists and engineers the ability to stabilize, block or steer light on demand.

A joint research team from the Gwangju Institute of Science and Technology (GIST) and the Korea Photonics Technology Institute has developed perovskite-enabled hybrid flexible copper indium gallium selenide (CIGS) thin-film solar cells that can convert all ultraviolet, visible and infrared sunlight into electric energy.

Current flexible CIGS thin-film solar cells are limited by a short wavelength band, from 300 to 390 nanometers, which is absorbed from the transparent electrodes at the top of the solar cell. They cannot convert short wavelength solar energy into electricity. The research team succeeded in developing CsPbBr₃ perovskite high-efficiency fluorescents that light up visible light bands by absorbing the light in the ultraviolet region, and applied them to the top of the transparent photoelectric layer of CIGS solar cells.

Researchers at the Massachusetts Institute of Technology (MIT) have improved a transparent and conductive coating material by increasing its electrical conductivity by 10 times. When this coating material was integrated into a perovskite solar cell, it boosted the stability and efficiency of the solar cell.

'The goal is to find a material that is electrically conductive as well as transparent,' explained the team, which would be ‘'useful in a range of applications, including touch screens and solar cells.'

A research group led by Prof. Liu Shengzhong from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences (CAS) and Prof. Yang Dong at Shaanxi Normal University have developed high efficiency semi-transparent perovskite solar cells by using MoO₃ sandwiched gold nanomesh (MoO₃/Au/MoO₃) multilayer as the transparent electrode. Combined with a superior heterojunction silicon solar cell, a high efficiency four-terminal perovskite/silicon tandem solar cell was obtained.

Tandem/multijunction structure has been proven to be an effective way to break the Shockley-Queisser limit. To obtain a high efficiency tandem solar cell, the key is to fabricate transparent electrode with high conductivity as well as high transparency through a mild method.

Researchers from King Abdullah University of Science and Technology (KAUST) in Saudi Arabia and University of Twente in the Netherlands have developed transparent conductive films that let through a broader range of the solar spectrum, which are set to increase the power conversion efficiency of perovskite-based multijunction solar cells beyond 30%.

A comparison of the used device test structures with different silicon bottom cells. Image taken from Advanced Functional Materials

Performance of perovskite-based tandem solar cells rests on the ability of the top cell to harvest the blue portion of the solar spectrum while letting through the near-infrared light. Conversely, the bottom cell only needs to absorb near-infrared light. "The semitransparency of the top cell depends on the optical bandgap and thickness of the perovskite thin film as well as the characteristics of the transparent electrodes, especially their sun-exposed side," explains study lead Stefaan De Wolf from theKAUST Solar Center.

MIT researchers have designed perovskite photovoltaic-powered sensors that could potentially transmit data for years before they need to be replaced. To this end, the team mounted thin-film perovskite cells as energy-harvesters on inexpensive radio-frequency identification (RFID) tags.

The cells could power the sensors in both bright sunlight and dimmer indoor conditions. Moreover, the team found the solar power actually gives the sensors a major power boost that enables greater data-transmission distances and the ability to integrate multiple sensors onto a single RFID tag.

Several research institutions in South Korea are actively conducting research and development on next-generation solar cells, heightening expectations for commercialization. The research team led by Prof. Yoon Soon-gil of Chungnam National University has developed a new graphene electrode to produce perovskite solar cells at a low temperature. In addition, the team led by Prof. Choi Kyoung-jin of the School of Materials Science and Engineering at UNIST has developed a new concept tandem solar cell using transparent conductive adhesives (TCA).

The graphene electrode developed by Professor Yoon's team can help create a perovskite solar cell at a low temperature and can raise both safety and economic efficiency.