Technical / research - Page 20

Researchers at the University of North Texas, Rochester Institute of Technology, University of North Carolina, National Renewable Energy Laboratory (NREL),  University of Oklahoma and NASA Glenn Research Center set out to deepen the understanding of perovskite photovoltaics' ability to recover, or heal, after radiation damage, by studying the effects of radiation based on different energy loss mechanisms from incident protons which induce defects or can promote efficiency recovery.

Dual dose irradiation experiments. Image from Nature Communications

The team designed a dual dose experiment first exposing devices to low-energy protons efficient in creating atomic displacements. Devices were then irradiated with high-energy protons that interact differently. Correlated with modeling, high-energy protons (with increased ionizing energy loss component) effectively anneal the initial radiation damage, and recover the device efficiency, thus directly detailing the different interactions of irradiation.

A research team, led by Northwestern scientists, has developed a method that could moves perovskite solar cells closer to industry adoption and widespread use. Using liquid crystals that can respond to temperature change and avoid accumulating precipitation, the group enabled the protection of large-area perovskite films. 

This approach led to a 22% efficiency and a stabilized efficiency of 21% for solar modules with enhanced damp heat (85% relative humidity at 85 degrees Celsius) stability and a size of 31 sq. centimeters.

Researchers from King Abdullah University of Science and Technology (KAUST), Princeton University, Marmara University, Academy of Sciences of the Czech Republic and Nano-C have designed a perovskite-silicon tandem solar cell with a top inverted perovskite cell relying on an electron transport layer (ETL) made of thermally evaporated buckminsterfullerene (C60).

In the “p-i-n” device structure, hole-selective contact p is at the bottom of intrinsic perovskite layer i with electron transport layer n at the top. Conventional halide perovskite cells have the same structure but reversed – a “n-i-p” layout. In n-i-p architecture, the solar cell is illuminated through the electron-transport layer (ETL) side; in the p-i-n structure, it is illuminated through the hole‐transport layer (HTL) surface.

Researchers at Argonne National Laboratory and Purdue University recently reported an effort to prevent perovskite solar cell degradation by tracking the movement of ions in perovskites. 

The team used X-rays at the Advanced Photon Source and a custom-built characterization platform to reveal the way ions move within different perovskite crystals under ultraviolet radiation (UV). Scientists are interested in testing material stability under UV because it can significantly degrade solar cell performance, sometimes by more than 50%, after extended exposure.

Researchers at Ulsan National Institute of Science and Technology (UNIST) and Korea University have reported efficient, stable tin–lead halide perovskites (TLHP)-based PV and photoelectrochemical (PEC) devices containing a chemically protective cathode interlayer—amine-functionalized perylene diimide (PDINN). Their work may advance the commercialization of perovskite solar cells (PSCs) and have potential in green hydrogen production technology, ensuring long-term operation with high efficiency. 

The presence of inherent ionic vacancies in tin-lead halide perovskites (TLHPs) has posed challenges, leading to accelerated device degradation through inward metal diffusion. To address this challenge, the research team developed the chemically protective cathode interlayer using amine-functionalized perylene diimide (PDINN). By leveraging its nucleophilic sites to form tridentate metal complexes, PDINN effectively extracts electrons and suppresses inward metal diffusion.

Researchers at the National University of Singapore (NUS), Chinese Academy of Sciences (CAS) and Avantama have developed a new interface using antimony doped tin oxides (ATOx), that creates a chemically stable interface between the cell layers that's more uniform, conducts electricity better, and is more transparent. This enabled reduced energy loss and improved cell efficiency - 25.7% (certified steady-state efficiency of 24.8%) for an area of 0.05 cm², retained under maximum power point tracking over 500 h and 24.6% (certified steady-state efficiency of 24.0%) for an area of 1 cm².

The team reported p-type antimony-doped tin oxides (ATOx) combined with a self-assembled monolayer molecule as an interlayer between the perovskite and hole-transporting layers (HTL) in inverted solar cells. The scientists said that ATOx increases the chemical stability of the interface; they showed that the redox reaction that commonly took place at the NiOx/perovskite interface is negligible at the ATOx/perovskite interface. 

Tin-based perovskite solar cells have attracted great research interest due to their excellent photovoltaic performance and environmentally friendly characteristics. However, TPSCs with ideal band gaps suffer from current losses, so new interface engineering strategies need to be developed to improve device performance. Researchers from Soochow University and Marmara University have reported high-performance tin-based perovskite solar cells (TPSCs) by constructing charge bridge paths. 

The authors propose a method to construct charge transfer pathways through a simple post-growth treatment of 3-aminomethylbenzo[b]thiophene (3-AMBTh) on a perovskite film. The selective reaction of 3-AMBTh with exposed FA⁺ on the perovskite surface suppresses the formation of iodine vacancy defects, resulting in a reduction in trap density.

Researchers at the University of Sheffield have used silver (Ag) particles to form a SnO₂:Ag nanoparticle composite transport layer, to improve the efficiency of perovskite solar cells.

SnO₂ is known as one of the most efficient transport layers for perovskite solar cells. Adding the Ag nanoparticles increased the recombination rate (detrimental for device performance), and the charge carrier transfer and extraction was also enhanced (beneficial for device performance). In order to balance these opposing factors, the nanoparticle concentration was optimized at an intermediate concentration with a corresponding power conversion efficiency increase from 13.4 ± 0.7 % for reference solar cells without nanoparticles to 14.3 ± 0.3 % for those with nanoparticles. 

Researchers at the University of Oxford, University of Toronto, Peking University, Kunming Medical University, Yunnan University, Chinese Academy of Sciences (CAS) and Academia Sinica have reported a chemically stable and multifunctional buffer layer material, ytterbium oxide (YbOx), for p-i-n perovskite solar cells (PSCs) by scalable thermal evaporation deposition. 

This YbOx buffer has been used in p-i-n PSCs based on narrow-bandgap perovskite light-absorbing layers, with certified power conversion efficiencies exceeding 25%.

Researchers at Seoul National University and Korea Advanced Institute of Science and Technology (KAIST) have developed highly efficient tandem perovskite light-emitting diodes (PeLEDs). This advancement may expedite the commercialization of perovskite light-emitting materials in next-generation display technologies.

The Ministry of Science and ICT (MSIT) announced that the team, led by Professor Lee Tae-woo from Seoul National University’s College of Engineering, has successfully created a high-efficiency and long-life hybrid tandem light-emitting device. This device combines metal halide perovskites with organic light-emitting diodes.