Stability - Page 6

Researchers from Northwestern University, University of Toronto and KAUST have hypothesized that perovskitoids, with robust organic-inorganic networks enabled by edge- and face-sharing, could impede ion migration. This addresses the issue of the migration of cations between 2D and 3D layers which results in the disruption of octahedral networks that leads to degradation in performance over time

The scientists explored a set of perovskitoids of varying dimensionality, and found that cation migration within perovskitoid/perovskite heterostructures was suppressed compared to the 2D/3D perovskite case. Increasing the dimensionality of perovskitoids improves charge transport when they are interfaced with 3D perovskite surfaces – the result of enhanced octahedral connectivity and out-of-plane orientation. 

Researchers from China's Zhejiang University, Westlake University, Southern University of Science and Technology, Chinese Academy of Sciences (CAS) and University of California Los Angeles in the U.S have reported a family of high-entropy organic–inorganic hybrid perovskites for photovoltaic applications.  

The scientists built, for the first time, an inverted perovskite solar cell relying on a high-entropy hybrid perovskite material. The result is a device with an improved open-circuit voltage and fill factor, due to reduced non-radiative recombinations and optimized interface.

Researchers at CHOSE (Centre for Hybrid and Organic Solar Energy, University of Rome Tor Vergata), BeDimensional, Istituto Italiano di Tecnologia and GreatCell Solar Italia recently addressed the stability issues presented by perovskite solar cells, by developing an industrial encapsulation process based on the lamination of highly viscoelastic semi-solid/highly viscous liquid adhesive atop perovskite solar cells and modules. 

Sketch of the structure of the mesoscopic n-i-p PSCs. Image credit: Nature Communications 

The encapsulant reportedly reduces the thermomechanical stresses at the encapsulant/rear electrode interface. The addition of thermally conductive two-dimensional hexagonal boron nitride into the polymeric matrix improves the barrier and thermal management properties of the encapsulant. Without any edge sealant, encapsulated devices withstood multifaceted accelerated ageing tests, retaining >80% of their initial efficiency.

Researchers from Zhejiang University, LinkZill Technology, Jilin University, and Linköping University have found that the electroluminescence rise time of perovskite LEDs (PeLEDs) can be reduced to microseconds using an individual-particle passivation strategy. This addresses a known issue with PeLEDs, that tend to have electroluminescence rise times over milliseconds due to ion migration in crystal structure, which is problematic for the development of high-refresh-rate displays.

The team demonstrated a second-generation digital display screen that uses perovskite light-emitting diodes instead of standard LED technology. In their study, the group made improvements to the device and demonstrated its sensing capability.

Researchers from Colombia's Universidad de los Andes recently set out to develop inverted perovskite solar cells (IPSCs) with a hole transport layer based on indium-doped nickel oxide. The result is a champion device that achieved an efficiency of 20.06% with remarkable stability.

The team explained that NiOx has an energy gap of over 3.5 eV, exceptional chemical stability, durability, low toxicity, and cost-effective processing. The scientists said that in the case of NiOx-based inverted perovskite solar cells, the doping approach has indeed paved the way for HTL optimization, frequently through observable improvements also at the interface level and in the perovskite layer.

Researchers from Monash University, Xi’an Jiaotong University, Tunghai University, the University of Oxford, National Central University, and the City University of Hong Kong have developed a strategy to enhance the stability and performance of perovskite solar cells (PSCs) through a mechanism described as 'self-healing'.

The team reported a living passivation strategy using a hindered urea/thiocarbamate bond Lewis acid-base material (HUBLA), where dynamic covalent bonds with water and heat-activated characteristics can dynamically heal the perovskite to ensure device performance and stability. 

Canon has announced that it has developed a high-performance material which is expected to improve the durability and mass-production stability of perovskite solar cells (PSCs). The Company aims to initiate mass production in 2025.

Canon stated that several issues are currently standing in the way of PSC commercialization. For one, the crystal structure of the perovskite layer (photoelectric conversion layer) is susceptible to the effects of water, heat, oxygen, etc. in the atmosphere, which results in low durability. Furthermore, it is difficult to achieve stable mass production when manufacturing perovskite solar cells with a large surface area. It has been recognized that a structure covering the perovskite layer is needed to solve these problems. Therefore, Canon developed a special functional material to coat the perovskite layer by applying the material technology it cultivated through the development of photosensitive members, a key component of multifunction office devices and laser printers.

Researchers at Rice University, along with researchers from several institutions in the U.S. and abroad, including Lawrence Berkeley National Laboratory; University of California, San Diego; University of Lille, National Center for Scientific Research (CNRS), Centrale Lille Institut; University of Artois; Northwestern University; Purdue University; University of Rennes, INSA Rennes, CNRS, Institut FOTON; Brookhaven National Laboratory; University of Washington; and Northwestern University, have described a way to synthesize formamidinium lead iodide (FAPbI₃) ⎯ the type of crystal currently used to make the highest-efficiency perovskite solar cells ⎯ into ultrastable, high-quality photovoltaic films. The overall efficiency of the resulting FAPbI₃ solar cells decreased by less than 3% over more than 1,000 hours of operation at temperatures of 85 degrees Celsius (185 Fahrenheit).

“Right now, we think that this is state of the art in terms of stability,” said Rice engineer Aditya Mohite, whose lab has achieved various improvements in perovskites’ durability and performance over the past several years. “Perovskite solar cells have the potential to revolutionize energy production, but achieving long-duration stability has been a significant challenge.”

Researchers from Australia's Griffith University and Queensland University of Technology have reported the fabrication of planar carbon-based perovskite solar cells (c-PSCs) with high efficiency and excellent stability, by employing electrochemically produced large-area phosphorene flakes as a hole-transporting layer (HTL). 

Carbon-based perovskite solar cells have attracted increasing attention due to their many advantages, including: ease of fabrication, the potential of assembling flexible devices, low manufacturing costs and more. However, c-PSCs suffer from limited hole extraction and high charge carrier recombination due to inadequate interface contact between the carbon electrode and perovskite film.

MIT researchers have developed a new computer vision technique that significantly speeds up the characterization of newly synthesized electronic materials. The technique automatically analyzes images of printed semiconducting samples and quickly estimates two key electronic properties for each sample: band gap and stability.

Overview of the synthesis and characterization pipeline for perovskite semiconductors. Image credit: Nature Communications

The new technique reportedly characterizes electronic materials 85 times faster compared to the standard benchmark approach. The researchers intend to use the technique to speed up the search for promising solar cell materials. They also plan to incorporate the technique into a fully automated materials screening system.