A new solar cell designed to work in locations such as windows and flexible surfaces where traditional panels cannot has been developed by nanotechnology researchers at the Hebrew University of Jerusalem. The device targets installations on building facades, architectural glass and curved structures where rigid modules are difficult to implement.
The research, led by Prof. Shlomo Magdassi and Prof. Lioz Etgar of the Hebrew University Institute of Chemistry and the Center for Nanoscience and Nanotechnology, points to new ways to embed solar technology in windows, building facades and curved surfaces without compromising appearance or performance. The approach focuses on semi-transparent, color-tunable perovskite solar cells that can blend in with their surroundings.
The findings, presented in EES Solar, discuss the fabrication of low-temperature processed, flexible, semi-transparent and color-tunable perovskite solar cells. The researchers can precisely tune how much light passes through and what color the cell is by adjusting the thickness of a transparent electrode layer, without changing the solar material itself.
This arrangement allows the device to reflect selected wavelengths of light while continuing to produce electricity from the remaining spectrum. It gives designers more freedom to choose different visual appearances and transparency levels, which is important for applications such as solar windows and glass partitions.
The core of the design is a pattern of microscopic polymer pillars, created using 3D printing. These tiny structures act as carefully shaped openings that regulate light transmission through the device, eliminating the need to replace the perovskite absorbing layer to achieve semi-transparency.
Because the method avoids high temperatures and toxic solvents, it is very suitable for more environmentally friendly production. The low-temperature, solvent-free process is compatible with flexible substrates and is intended to support the scalable production of solar cells for real-world use.
“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.”
In laboratory tests, the flexible solar cells achieved an energy conversion efficiency of up to 9.2 percent, with an average visible transparency of approximately 35 percent. They also maintained stable performance after repeated bending and during extended use, which are important benchmarks for use in architectural and other mechanically flexible environments.
“What is especially exciting is that we can customize both the appearance and flexibility of the device, without sacrificing performance,” said Prof. Etgar. “That makes this technology particularly relevant for solar windows and for adding solar functionality to existing buildings.”
The team next plans to focus on improving long-term durability through protective encapsulation and barrier layers to protect the perovskite material from moisture and oxygen. The goal is to bring the technology closer to commercial use by increasing stability and refining the manufacturing process.
Research report:Semi-transparent perovskite solar cells with adjustable color and 3D pillar structure
