Sebastian Stasch | DELO Industrial Adhesives: How do you UV-cure encapsulation adhesives through barrier foils that are specifically designed to block UV light?
03:06 - 04:41
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Summary of the clip:
How do you achieve rapid, high-reliability encapsulation of perovskite and organic photovoltaics without degrading their highly sensitive active layers?
Roll-to-roll processing of flexible photovoltaics requires encapsulation materials that can be applied at high throughput via slot-die or roll coating. The primary challenge lies in achieving rapid, low-temperature curing on flexible barrier foils that incorporate integrated UV filters designed to protect the active organic or perovskite layers from degradation.
To bypass these protective UV filters, advanced encapsulation formulations are engineered for long-wavelength photo-initiation, curing efficiently at 400 nm or 460 nm. This selective spectral activation ensures complete cross-linking through the barrier film without exposing the underlying photoactive materials to damaging shortwave ultraviolet radiation.
The resulting barrier must deliver high peel resistance to maintain mechanical integrity under continuous flexing, alongside high optical transparency to prevent efficiency losses. Furthermore, the adhesive must exhibit an exceptionally low water vapor transmission rate (WVTR) to prevent moisture ingress while remaining chemically inert to avoid destructive interactions with the organic or perovskite layers.
In this short video, you can learn:
* How specialized adhesives bypass the UV-blocking filters of barrier foils using targeted 400 nm and 460 nm photo-initiation.
* The critical mechanical and optical requirements for flexible encapsulation, including high peel resistance and maximum transparency.
* The dual challenge of achieving a low water vapor transmission rate (WVTR) while ensuring zero chemical interaction with sensitive active layers.
📋 **Clip Abstract** The speaker explains how UV-curable adhesives formulated for 400 nm and 460 nm wavelengths can cure through protective barrier foils to encapsulate organic and perovskite photovoltaics. He details the key performance requirements for these adhesives, focusing on slot-die or roll coating compatibility, high peel resistance, low WVTR, and chemical compatibility with the active device layers.
🎤 Speaker: Sebastian Stasch
🏢 Company: DELO Industrial Adhesives
📅 Event: Perovskite Connect 2025
📍 Location: Estrel Congress Centre, Berlin (Co-located with TechBlick's Future of Electronics RESHAPED show)
🌐 Learn more at the next TechBlick event: https://www.techblick.com
#NearUVCuring, #BarrierFilms, #OpticalAdhesives, #RollToRollProcessing, #PerovskitePhotovoltaics, #PrintedElectronics
This is a highlight of the presentation:
Pioneering the Future: DELO's Advanced Adhesives Enhance Perovskite Solar Cell Protection
More Highlights from the same talk.
06:30 - 07:58
What happens when edge-sealing adhesives diffuse directly into the active layers of a perovskite solar cell?
What happens when edge-sealing adhesives diffuse directly into the active layers of a perovskite solar cell?
Encapsulating perovskite solar cells is far more complex than simple face-lamination due to the aggressive chemical interactions occurring at the interfaces. During edge sealing, the adhesive must come into direct physical contact not only with the glass or PET substrate, but with every layer of the active stack, including the anode, cathode, charge transport layers, and the perovskite absorber itself.
Even without direct face contact, volatile components or reactive monomers from the liquid adhesive can diffuse through the porous electrode layers. This interfacial diffusion can trigger rapid chemical degradation of the perovskite crystal structure, destroying the cell before it ever leaves the laboratory.
To evaluate these risks, rigorous material compatibility screenings are performed on specific configurations, such as CsFA (cesium formamidinium) perovskite stacks on PET substrates. Developing a universally compatible adhesive remains a major challenge, as minor variations in the chemical composition of different perovskite precursor formulations change how they react with raw adhesive resins.
In this short video, you can learn:
* Why edge-sealing adhesives must maintain multi-interface chemical compatibility across the entire device stack.
* The mechanism of adhesive monomer diffusion through porous electrodes to active perovskite absorbers.
* How specialized test stacks like CsFA-on-PET are deployed to screen raw materials for chemical compatibility.
📋 **Clip Abstract** This clip details the interface challenges of edge-sealing perovskite solar cells, highlighting how adhesives interact directly with multiple device layers. It emphasizes the risks of monomer diffusion and outlines compatibility testing methodologies used on CsFA perovskite stacks.
#EdgeSealEncapsulation, #AdhesiveDiffusion, #CsFAPerovskite, #BarrierAdhesives, #PerovskitePhotovoltaics, #FlexibleElectronics
09:12 - 11:05
Why do standard epoxy adhesives completely destroy perovskite solar cells while acrylates leave them unharmed?
Why do standard epoxy adhesives completely destroy perovskite solar cells while acrylates leave them unharmed?
Selecting the wrong base chemistry for a perovskite encapsulation adhesive can lead to catastrophic device failure within days, even under inert conditions. Systematic raw material screenings reveal a stark divergence in compatibility between epoxy-based and acrylate-based systems, which are the two primary families of low-permeation sealants.
During raw material testing of 21 epoxy and 43 acrylate resins directly on perovskite layers, epoxies demonstrated extreme incompatibility. Within just seven days inside an inert glove box, the perovskite structure behind the epoxy adhesive completely dissolved and degraded, while the acrylate-treated samples remained entirely stable and intact.
To validate long-term survival, these formulations undergo accelerated aging tests at high temperatures and humidity levels. By subjecting the compatible acrylate-based adhesives to damp heat conditions, researchers can verify if the encapsulated perovskite retains its active black phase or degrades into inactive lead iodide.
In this short video, you can learn:
* The dramatic difference in perovskite chemical compatibility between epoxy and acrylate raw materials.
* How to design a screening protocol using inert glove box storage and visual degradation analysis.
* The methodology for accelerating chemical degradation using high-temperature and high-humidity environments.
📋 **Clip Abstract** This clip reveals critical material screening data comparing 21 epoxy and 43 acrylate raw materials placed in direct contact with perovskite layers. It highlights the surprising chemical instability of epoxies relative to acrylates and demonstrates how accelerated environmental testing is used to verify barrier performance.
#PerovskiteEncapsulation, #AcrylateAdhesives, #DampHeatTesting, #LeadIodideDegradation, #PerovskitePhotovoltaics, #PrintedElectronics