Stability - Page 8

Researchers at HZB's HySPRINT Innovation Lab, China's Tianjin University of Technology and Tianjin Institute of Power Sources have developed a non-laser additive method for manufacturing perovskite solar modules, in which an adjustable wire mask (AWM) was used to form the channels that were traditionally scribed by lasers. 

When module channels are made by conventional laser scribing, the heat-sensitive perovskite materials decompose, and the decomposition of perovskites in the open channel leads to reduced module stability. The electrode corrosion caused by the direct contact between the exposed perovskites and the metal electrode significantly increases the series resistance of the module. In this recent work, the team developed a non-laser additive method for manufacturing perovskite solar modules, in which an adjustable wire mask (AWM) was used to form the channels that were traditionally scribed by lasers. This method for making modules prevents contact between perovskites and electrodes. All layers, including perovskites, hole/electron transporting, and passivating and electrode layers, were fabricated via vapor-phase deposition, and by tuning the precursor composition, a power conversion efficiency (PCE) of 21.7% was obtained (0.1 cm²). 

Researchers at City University of Hong Kong, Zhejiang University and The Hong Kong University of Science and Technology have designed a unique triple-layer thermochromic perovskite window (MTPW) that enables sufficient water vapor transmission to trigger the thermochromism but effectively repel detrimental water and moisture to extend its lifespan. The scientists explained they drew inspiration from the structure of medical masks.

Schematic of the trilayer structure and working principle of an antivirus medical mask. b Schematic of the trilayer structure and working principle of the MTPW for repelling water and excess water vapor. Image from Nature Communications

This research addresses the two main challenges hindering the development of thermochromic perovskite smart windows, namely, poor durability and optical blurriness. The MTPW demonstrates superhydrophobicity and maintains a solar modulation ability above 20% during a 45-day aging test, with a decay rate 37 times lower than that of a pristine TPW. It can also immobilize lead ions and significantly reduce lead leakage by 66 times.

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.

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 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 the University of Michigan and Arizona State University have examined bulky "defect pacifying" molecules as a way to increase the stability and overall lifespan of perovskite materials.

The team expects this novel way of preventing perovskite materials from degrading quickly could help enable solar cells estimated to be two to four times cheaper than today's thin-film solar panels.

Researchers at the Chinese Academy of Sciences (CAS), Shanghai Jiao Tong University School of Medicine and the University of Electronic Science and Technology of China (UESTC) have presented a simple and economical encapsulation strategy with shellac to protect perovskite solar cells (PSCs) under various accelerated degradation experiments. 

The shellac-encapsulated (SE) PSC modules reportedly passed outdoor stability, UV preconditioning, and hail tests according to the International Electrotechnical Commission 61215 standard (IEC61215). 

A collaborative team of researchers, including ones from Uppsala University, CNR-SCITEC, Fraunhofer ISE, University of Cambridge, Empa, EPFL and additional institutes, recently introduced an unexplored dimethylphenethylsulfonium iodide (DMPESI) molecule to post-treat formamidinium lead iodide perovskite films. The treated films showed outstanding stability upon light soaking and remarkably remains in black-phase after 2 years ageing under ambient condition without encapsulation. 

Fresh and 24-month aged unencapsulated perovskite film (1.0 cm by 2.0 cm) without and with DMPESI treatment of different concentrations. Image from Nature Energy

The DMPESI-treated PSCs deliver a breakthrough record in operational stability of highly-efficient PSCs with less than 1% performance loss after more than 4500 h at maximum power point tracking, yielding an extraordinarily high theoretical T80 of over 9 years under continuous 1-sun illumination, which would correspond to a photon flux of an outdoor PV installation in Sweden or Germany (1,000 kWh m−2 per year) of over 78 years. 

Researchers from China's Shanghai University of Engineering Science have developed a novel solar spectral converter using a GdPO₄ glass-ceramic (GC) material doped with praseodymium (Pr) and europium (Eu) ions. This technology could lead to notable boosts in performance and applicability of solar cells.

The main purpose of GdPO₄-GC:Eu³⁺/Pr³⁺ is to absorb UV photons from solar radiation and re-emit them as visible light. This is possible thanks to the efficient energy transfer that happens between the ions in the material.

Researchers at Germany's Forschungszentrum Jülich have reported a method to fabricate >1-micrometer thick perovskite films by employing hole-transporting bilayers of self-assembled monolayers (SAMs) and poly[bis(4-phenyl) (2,4,6-trimethylphenyl)amine] (PTAA). Recognizing the critical role transport layers play in exacerbating thickness-dependent losses, the team optimized a dual-layer hole transport architecture to reduce resistive losses and recombination. The authors achieved remarkable efficiency retention at over 1 micron thickness.

This work focuses on a solar cell architecture that decouples thickness from efficiency limitations. By sandwiching specialty organic films around the perovskite layer, the authors enabled micron-scale thicknesses without forfeiting peak performance. Their design notably achieves a remarkable 20.2% efficiency at over 1 micron thickness with minimal losses compared to thinner versions.