Technology highlights | Perovskite Connect
Here are short video highlights from recent TechBlick events. In this issue:
Join us at our next event
Meet the speakers and exhibitors in person - see the full programme and register on our website.
Can graphene carbon inks genuinely disrupt the silver metallization monopoly in solar cells? The economic and ecological strain of silver metallization in the photovoltaic industry is driving the search for viable carbon-based alternatives. Silver pricing has doubled over the past two years, with the solar sector now consuming nearly 20% of the global silver supply. Graphene-based conductive inks offer a direct, drop-in replacement that addresses these supply-chain vulnerabilities. By leveraging optimized graphene dispersions, these newly developed carbon inks achieve a projected cost reduction of 87% compared to commercial silver inks at scale. Beyond raw material economics, the transition to carbon eliminates carbon-intensive and toxic mining processes. This translates to an environmental footprint that is roughly two orders of magnitude more sustainable. This technical shift enables a clean, one-to-one replacement of metal electrodes in printed electronics and solar cells.
Can a few nanometers of atomic layer deposition solve the notorious degradation challenge of perovskite solar cells? Perovskite solar cells offer exceptional light-to-electricity conversion efficiency and low potential manufacturing costs. However, their industrial viability is severely bottlenecked by poor long-term stability and rapid degradation when exposed to ambient moisture, heat, and oxygen. By replacing standard bathocuproine (BCP) buffer layers with spatial atomic layer deposition (ALD) of thin tin oxide (SnOx), researchers can dramatically improve current densities and device lifetimes. Adding even a minute sub-nanometer capping layer of aluminum oxide (Al2O3) creates a highly robust barrier that practically halts performance decay, opening a clear path to commercial durability. To make this commercially viable, manufacturers must transition from slow vacuum batch systems to high-speed, atmospheric-pressure roll-to-roll configurations. SparkNano's spatial ALD technology enables this transition, delivering conformal, pinhole-free barrier and charge-transport layers at high throughput.
How do you achieve a 2-nanometer crystalline grain size in low-temperature solution-processed thin films? To function effectively as ultra-thin charge transport layers in solar cells and OLEDs, colloidal nano-inks must meet stringent electronic-grade requirements. PINA Creation's metal oxide inks are formulated using green solvents like ethanol, isopropyl alcohol (IPA), and water, ensuring compatibility with standard roll-to-roll, slot-die, and blade-coating manufacturing lines. Crucial to industrial adoption is dispersion stability and shelf life; these formulations maintain their performance without aggregation or degradation for eight to twelve months. Minimizing nanoparticle size is critical to achieving dense, pinhole-free films that facilitate efficient charge extraction while maintaining high optical transparency. Dynamic Light Scattering (DLS) data of their zinc oxide ink confirms a highly monodisperse nanoparticle size distribution below 10 nanometers in IPA. Transmission Electron Microscopy (TEM) characterization of the resulting thin films reveals exceptionally high crystallinity, with individual crystallite sizes measuring approximately 2 nanometers.
Can low-temperature screen-printed metallization replace evaporated silver grids in industrial-scale perovskite-silicon tandems? At the laboratory scale, perovskite-silicon tandem solar cells have achieved remarkable efficiencies, such as the 30.8% demonstrated by CEA on a 9 square centimeter aperture. However, these record-setting devices rely on evaporated silver grids that suffer from severe shading losses of up to 14%. Transitioning to commercial manufacturing requires high-throughput metallization techniques that do not compromise the delicate perovskite top cell. To address this challenge, researchers developed a low-temperature screen-printing solution utilizing silver pastes that cure below 120°C. This specialized thermal window is critical to prevent thermal degradation of the underlying perovskite and organic transport layers. By optimizing the grid design, the team successfully mitigated grid shading losses, reducing them from 14% to under 3%.
Why are 26% efficient perovskite-silicon tandems dead on arrival in utility-scale markets? TotalEnergies, in collaboration with IPVF, has conducted extensive total cost of ownership (TCO) and Levelized Cost of Energy (LCOE) assessments on perovskite-silicon tandem systems. Despite the excitement surrounding laboratory records, the developer perspective shows that a tandem efficiency of 26% to 27% is commercially insufficient to compete with incumbent monocrystalline silicon. To achieve economic parity, perovskite tandems must target significantly higher starting efficiencies while maintaining degradation profiles that match crystalline silicon. The commercial viability of these cells is not dominated by the underlying manufacturing technology or the choice between two-terminal (2T) and four-terminal (4T) configurations, but strictly by starting efficiency and degradation. This reality check highlights the rigorous commercial barriers that emerging photochemistry must overcome.
Can We Design a Perovskite Solar Cell That Is 100% Recyclable Without Scraping the Electrodes? Standard photovoltaic recycling is an energy-intensive, destructive process that usually recovers only bulk glass or silicon fractions. SOLRA-PV overcomes this bottleneck by utilizing a triple-mesoscopic oxide scaffold printed via screen printing. By sequentially printing titania (TiO2), zirconia (ZrO2), and indium tin oxide (ITO) layers on a transparent conductive oxide substrate, they create a highly porous matrix that can be infiltrated by a perovskite precursor in a single step. Because the active perovskite material is deposited as the final phase via slot-die coating and remains chemically accessible within the mesoporous scaffold, it can be completely dissolved back out of the matrix using a simple solvent wash. This non-destructive process preserves the underlying screen-printed titanium and zirconium oxide ceramic layers entirely.
Can printed perovskites truly survive 10,000 hours of extreme damp heat without catastrophic degradation? Stability has historically been the primary critique of perovskite optoelectronics, but advanced barrier engineering is rapidly closing the reliability gap. Under rigorous independent testing in France and Taiwan, custom perovskite cells have successfully retained over 90% of their initial efficiency after 10,000 hours of continuous exposure to damp heat testing at 85°C and 80% relative humidity. This performance is mirrored in continuous maximum power point tracking and short-circuit testing under intense light sources. The core breakthrough enabling this moisture resistance is a proprietary three-step encapsulation process that operates with a mere one-millimeter active edge boundary. Typical industrial barrier layers require wide perimeter seals that eat up valuable surface area, rendering them unusable for space-constrained IoT devices.
Why does Couette flow limit the ultimate speed of roll-to-roll spatial atomic layer deposition? Spatial Atomic Layer Deposition (S-ALD) achieves deposition speeds up to 100 times faster than conventional temporal ALD by physically separating precursor zones rather than cycling gas pulses. While this allows continuous atmospheric processing, the absolute throughput limits of this geometry are governed by fluid dynamics rather than chemical kinetics. At high linear velocities, a major bottleneck emerges in the form of drag flow and Couette flow. The moving substrate drags a boundary layer of gas with it, threatening to carry precursor molecules (such as trimethylaluminum) across the nitrogen isolation barriers and directly into the reactant zone. To avoid parasitic gas-phase reactions and preserve self-limiting surface monolayer growth, the design of the deposition head must meticulously balance gas flow rates and nozzle spacing.
Why is monolithic two-terminal integration winning the tandem PV race over four-terminal alternatives? Integrating perovskites with silicon bottom cells in a monolithic, two-terminal (2T) tandem architecture offers a significant performance delta over four-terminal (4T) configurations. By integrating all active layers into a single, cohesive cell structure, optical parasitic absorption is minimized, yielding superior power conversion efficiencies. Additionally, the elimination of redundant substrates, transparent conductive oxides, and external wiring reduces raw material costs and simplifies module assembly. From a reliability and packaging standpoint, the 2T design provides crucial advantages. Structuring subcells within a single package minimizes scribe line complexity and boundary exposure, protecting the moisture-sensitive perovskite absorber from environmental degradation. Furthermore, this monolithic platform creates a direct evolutionary pathway toward multi-junction stacks, where three or more energy-harvesting layers can be stacked sequentially. While 4T architectures offer relaxed current-matching requirements, they suffer from high balance-of-system costs and complex field deployment.
Why must champion-efficiency perovskite chemistries be discarded when scaling up to high-throughput slot-die coating? Transitioning perovskite PV technology from spin-coated laboratory pixels to scalable industrial formats requires a fundamental shift in material processing and architecture. While spin-coating enables rapid chemical screening on tiny substrates, it cannot scale to commercial dimensions. By moving to slot-die coating on larger substrates—such as 150 mm and eventually 310 x 400 mm glass—issues like fluid dynamics, film drying, annealing uniformity, and area-scaling losses become the dominant technical challenges. Interestingly, achieving stable, large-area manufacturing often requires purposefully avoiding the highly volatile "champion" chemistries used to claim record-breaking laboratory efficiencies. These high-performance laboratory formulas frequently lack the thermal and structural stability required to survive real-world environmental stress over decades. Instead, a more robust and intrinsically durable chemistry must be optimized, accepting a minor initial efficiency trade-off in exchange for scalable reliability.
Comments