A new study highlights a semi-transparent, color-tunable solar cell designed to work in places traditional panels can’t, like windows and flexible surfaces. Using a 3D-printed pillar structure, the researchers can fine-tune how much light passes through and what color the cell appears, without changing the solar material itself. The result is a system that balances energy output with durability, while giving designers far more control over how the technology looks and functions.

The research was led by Prof. Lioz Etgar and Prof. Shlomo Magdassi and from the Institute of Chemistry and the Center for Nanoscience and Nanotechnology at Hebrew University. Their team lead by Dr. Vikas Sharma developed a semi-transparent, flexible perovskite solar cell that can generate electricity while allowing designers to control how much light passes through it and what color it appears. The advance points to new ways of embedding solar technology into windows, building façades, and curved surfaces without compromising appearance or performance.

At the heart of the design is a pattern of microscopic polymeric pillars created using 3D printing. These tiny structures act like carefully shaped openings that regulate light transmission, eliminating the need to alter the solar material itself. Because the method avoids high temperatures and toxic solvents, it is well suited for flexible surfaces and more environmentally friendly manufacturing.

“Our goal was to rethink how transparency is achieved in solar cells for applications in Building Integrated Photovoltaics,” said Prof. Shlomo Magdassi. “By using 3D-printed polymeric structures, we can precisely control how light moves through the device in a way that is scalable and practical for real-world use.”

The researchers also showed that the solar cells’ appearance can be tuned by color. By adjusting the thickness of a transparent electrode layer, the device reflects selected wavelengths of light, giving the solar panel different colors while continuing to produce electricity.

“What is particularly exciting is that we can customize both the device’s appearance and its level of transparency,” said Prof. Lioz Etgar. “That makes this technology particularly relevant for solar windows and for adding solar functionality to existing buildings.”

In laboratory tests, the flexible solar cells reached power conversion efficiencies of up to 9.2%, with about 35 % average visible transparency. They also maintained stable performance after repeated bending and during extended operation, key benchmarks for use in real architectural environments.

Looking ahead, the team plans to focus on improving long-term durability through protective encapsulation and barrier layers, with the goal of moving the technology closer to commercial use.