A recent study by researchers at Israel's Hebrew University of Jerusalem reports the development of a semi-transparent, color-tunable perovskite solar cell designed for integration into surfaces such as architectural glass and flexible substrates where conventional panels are not suitable. The devices are fabricated using a low-temperature process that combines plasma-assisted deposition of the electron transport layer with inkjet printing of 3D polymer pillars from a solvent-free, UV-curable monomer.
Schematic presentation of the main steps involved in the fabrication of a colorful, semi-transparent, flexible perovskite solar cell. Image from : EES Solar
The work, led by Prof. Shlomo Magdassi and Prof. Lioz Etgar from the Institute of Chemistry and the Center for Nanoscience and Nanotechnology, presents a method for controlling optical and mechanical properties without modifying the perovskite absorber layer. Optical transparency is adjusted by the spacing of the micrometric polymer pillars, which act as “optical holes” within the perovskite layer, enabling a balance between active area, average visible transmittance, and mechanical robustness.
“Our goal was to rethink how transparency is achieved in solar cells,” said Prof. Magdassi. “By using 3D-printed polymer structures made from non-toxic, solvent-free materials, we can precisely control how light moves through the device in a way that is scalable and practical for real-world use.”
Color tuning is realized through a transparent top electrode that forms an optical cavity, selectively reflecting specific wavelengths while transmitting the rest to the perovskite absorber. By varying the thickness of this transparent electrode, the team obtains different perceived colors while maintaining semi-transparency. “We can customize both how the device looks and how flexible it is, without sacrificing performance,” noted Prof. Etgar.
The flexible devices demonstrated power conversion efficiencies up to about 9.2% with average visible transparency around 35% in neutral configurations, and approximately 6–8% for colored variants with AVT above 30%, retaining stable performance under repeated bending. These characteristics support their potential use in solar-integrated windows and façades, particularly for retrofitting existing glazing.
Future work will focus on improving long-term stability, including optimization of encapsulation and barrier layers, to facilitate scale-up and practical deployment in building-integrated and flexible photovoltaic applications.
