Femtosecond laser processing for micro- and nanopatterning of metal halide perovskite thin films for enhanced light management in solar cells

Project Information

SPARKLES

Grant agreement ID: 101149132

DOI

10.3030/101149132

Project closed

EC signature date 14 March 2024

Start date 1 May 2024

End date 30 April 2026

Funded under

• Marie Skłodowska-Curie Actions (MSCA)

Total cost

No data

EU contribution

€ 175 920,00

Coordinated by

KATHOLIEKE UNIVERSITEIT LEUVEN
Belgium

Periodic Reporting for period 1 - SPARKLES (Femtosecond laser processing for micro- and nanopatterning of metal halide perovskite thin films for enhanced light management in solar cells)

Reporting period: 2024-05-01 to 2026-04-30

Summary of the context and overall objectives of the project

Light management is a key factor in many optoelectronic devices and especially in solar cells, where controlling how light is absorbed or reflected directly impacts device performance. However, although many strategies have been developed over the years, their implementation is not always straightforward, particularly when dealing with fragile or chemically sensitive materials. This is the case of metal halide perovskite thin films solar cells. Metal halide perovskites are highly promising materials for photovoltaics due to their excellent optoelectronic properties and rapidly increasing efficiencies, but their phase degradation and chemical fragility strongly limits the use of conventional light management approaches. Traditional nanostructuring techniques, such as lithography or wet chemical patterning, often involve harsh processes, multiple steps or chemicals that can dagame the perovskite layer, making them difficult to apply in a scalable way.
The SPARKLES project addresses this challenge by proposing a new and compatible strategy based on femtosecond laser processing. In particular, it uses laser-induced periodic surface structures (LIPSS), which are self-organized nanoscale patterns formed through light interference during laser irradiation.Because of this physical mechanism, the process is fast, mask-free and potentially scalable to large areas, while remaining gentle enough to be compatible with sensitive materials such as perovskites.
For this reason, SPARKLES explores femtosecond laser patterning as a realistic alternative to conventional nanofabrication techniques. The project is structured around four main objectives:
(1) the fabrication of LIPSS on thin perovskite films
(2) the deposition of perovskite layers on laser-structured substrates to explore different device configurations
(3) the understanding of how laser processing affects material properties and light matter interaction
(4) the implementation of these strategies in working solar cell devices

Overall, the project aims to develop a scalable and material-friendly approach to improve light management in perovskite solar cells, bridging the gap between advanced nanostructuring concepts and real photovoltaic applications.

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

The SPARKLES project successfully developed and demonstrated a new laser-based strategy for scalable light management in perovskite solar cells. The approach is based on femtosecond LIPSS, enabling the formation of nanopatterns in a fast, single-step and material compatible way. This work provides a novel alternative to conventional nanofabrication techniques, which are often too complex or too invasive for perovskite-based devices.
The project explores different LIPSS nanopatterning strategies and architectures. This included the fabrication of LIPSS on perovskite thin films, as well as the deposition of the perovskite on pre-patterned substrates with LIPSS to study different light management architectures.
Key scientific and technological achievements include:
1. Demonstration of LIPSS on perovskite materials, confirming the feasibility of patterning directly the absorber layer.
2. Establishment of controlled laser nanopatterning strategies to tune surface periodicity and morphology within the sub-micrometer range for enhanced light trapping.
3. Development of the synthesis methods for enabling systematic top-down and bottom-up light management approach.
4. Analysis of material modifications caused by the laser processing and their implication in the final performance
5. Demonstrated the enhanced absorption in a simplified architecture due to LIPSS

SPARKLES bridges ultrafast laser processing, material science and photovoltaic device engineering. The project opens new pathways toward scalable, low-cost and industry compatible nanostructuring strategies in solar cells and related optoelectronic technologies.

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

SPARKLES introduces fs LIPSS as a new and scalable approach for nanopatterning metal halide perovskite thin films. This goes beyond conventional methods, which usually rely on multi-step lithography or chemical processes that are incompatible with this kind of materials. The project shows that ultrafast laser processing can directly create controlled nanoscale patterns in a singles step, without masks or wet chemistry. This makes the approach faster, simpler and more compatible with sensitive active materials. Importantly, the laser treatment is compatible with perovskites and can be applied in a way that preserves the material without causing degradation.

Beyond the formation of LIPSS, the project also shows that femtosecond laser processing can modify the optical response of the material. In particular, characterization results indicate improvements in photoluminescence intensity after the laser treatment, suggesting beneficial changes in the optoelectronic properties of the system. These findings are not limited to perovskite materials. They are also relevant for other energy-related thin film materials where light management is important but conventional nanopatterning is limited by material fragility. This extends the potential impact of the approach to a broader range of optoelectronic technologies.