Stability - Page 17

Scientists at the U.S. Department of Energy’s National Renewable Energy Laboratory (NREL), CU-Boulder and the University of Toledo have demonstrated a tin-lead perovskite cell that overcomes problems with stability and improves efficiency. The new cell, a tandem design with two layers of perovskites, reached 25.5% efficiency.

The new cell also retained 80% of its maximum efficiency after 1,500 hours of continuous operation, or more than 62 days.

Researchers at Florida State University (FSU), in collaboration with ones from Argonne National Laboratory, have examined what happens when a halide perovskite faces real-world conditions, as opposed to pristine conditions of a chemistry lab.

They found that stressing halide perovskites with light and electric fields can create changes in the basic properties of the material and distort the lattice structure that is crucial to keeping this material stable.

Scientists from Imperial College London, the University of Surrey, the University of Nottingham, research institute UCL, Switzerland-based Fluxim and London South Bank University have designed a perovskite solar cell that integrates a ferrocene co-mediator interlayer at the interface between the spiro-OMeTAD hole transport layer (HTL) and the active perovskite material.

The team noted that the migration of lithium is critical in the degradation of spiro-OMeTAD-based devices, which is accelerated at higher temperatures, leading to the rapid degradation of the perovskite. The scientists described ferrocene as a sandwich structured material that is highly stable and can be used as a low-cost transition metal complex.

Researchers from Chonnam National University in South Korea, Shivaji University in India, the Belgian research institute KU Leuven and Cardiff University in the UK have built an all-inorganic perovskite solar cell with a terbium doped solar absorber, which reportedly increases thermal stability.

The scientists developed a low-cost and simple hot-air method and also used terbium doping and quantum passivation techniques to stabilize the perovskite phase in the ambient conditions - with all processes carried out in ambient conditions.

In its recent report, the US Department of Energy Solar Energy Technologies Office (SETO) outlined the main technical challenges, commercialization risks and opportunities and the efforts being made to overcome the obstacles standing before the commercialization of perovskite solar cells.

It's important to note that while SETO mentions that most of the development in the solar field in the next few years will rely on silicon and CdTe, it sees potential in nascent technologies like halide perovskites.

Researchers from EPFL, Tianjin University, Nanjing Tech University, The University of Tokyo, Shanghai University and Toyota Motor Corporation have used ionic liquids (ILs) with halide anions as additives to improve the performance and stability of a perovskite solar cell.

Image from study in Cell Reports Physical Science

Ionic liquids are viewed as a "greener" alternative to organic solvents due to their lower volatility and flammability, as well as to their wide liquid-state window.

A research team, co-led by scientists from City University of Hong Kong (CityU) and Imperial College London, has developed highly efficient and stable perovskite solar cells.

Among the different types of perovskite solar cells, those with an inverted design configuration have exhibited exceptional stability, making them good candidates to reach the lifetime of commercial silicon solar cells. However, perovskite materials include chemically reactive components, which can easily volatilize and degrade under high temperature and humidity, shortening the solar cells' operational lifetime. Also, there is still a need for strategy to enhance the efficiency of inverted perovskite solar cells up to 25% to rival that of silicon solar cells, while maintaining their stability.

Researchers from the University of Toronto and their international collaborators have leveraged quantum mechanics to optimize the active layer within an inverted perovskite solar cell.

"Perovskite crystals are made from a liquid ink and coated onto surfaces using technology that is already well-established in industry such as roll-to-roll printing," says Hao Chen, a post-doctoral researcher in Sargent's lab and one of four co-lead authors of a new paper published in Nature Photonics. "Because of this, perovskite solar cells have the potential to be mass produced at much lower energy cost than silicon. The challenge is that right now perovskite solar cells lag traditional silicon cells in stability. In this study, we aimed to close that gap."

A research team, led by Professor Ivan Mora Ser from the Institute of Advanced Materials (INAM) of the Universitat Jaume I of Castell, has improved the efficiency and durability of tin perovskite solar cells. The cells presented in the recent study exceeded 1,300 hours of operational stability, thanks to the incorporation of additives in the preparation of the devices.

Tin-based halide perovskites are being studied as potential candidates for lead-free perovskite solar cells. In the case of tin, an efficiency of more than 14% has been achieved so far, but it has major stability problems. This new work has introduced a combination of dipropylammonium iodide and sodium borohydride, two additives that have made it possible to prepare devices with PCEs of more than 10%, which boast greater stability and have maintained 96% of the initial PCE after 1,300 hours under solar illumination in a nitrogen atmosphere.

Researchers at the UCLA Samueli School of Engineering, along with colleagues from five other universities around the world, have discovered a major reason why perovskite solar cells degrade in sunlight, causing their performance to suffer over time.

The team demonstrated a simple manufacturing adjustment to fix the cause of the degradation, addressing one of the biggest hurdles toward the commercialization of the perovskite-based solar cell technology.