Technology that can charge batteries directly from a smartphone screen has emerged, and expectations are high that it will lead the way to eco-friendly energy when commercialized in the future.

Professor Seo Kwan-yong's team from the Department of Energy and Chemical Engineering at UNIST announced on the 20th that they have introduced a new type of transparent solar cell and module that has high efficiency while maintaining the colorless and transparent properties like glass.

By introducing the 'all-back-contact' design, which places all components of the solar cell on the back, colorless transparency was secured.

It has achieved both high efficiency and aesthetics, which are essential for transparent solar cells.

The research team developed a 'seamless modularization' technology that eliminates the gaps between elements without using metal wires. It solved the problem of the existing modularization method damaging the appearance of transparent solar cells due to the gaps between elements and opaque metal wires.

The developed 16㎠-sized transparent solar cell module achieved high efficiency of 14.7% at a transmittance of 20% while maintaining aesthetics similar to a single element.

We have also succeeded in charging our smartphones using natural sunlight. It also demonstrates the potential for small mobile device screens to be used as energy sources.

Researcher Park Jeong-hwan and Research Assistant Professor Lee Kang-min said, “This study fundamentally solved the aesthetic problems of the existing solar cell modularization method through a new device structure design,” and “It suggests the possibility that transparent silicon solar cells can be utilized in various industrial fields such as building and automobile glass as well as small devices.”

Professor Seo Gwan-yong said, “We have opened a new path for modularization research that is essential for commercializing transparent silicon solar cells,” and “We plan to continue additional research so that transparent solar cells can become a core technology for the eco-friendly future energy industry.”

The research was published on August 7 in the international academic journal PNAS (Proceedings of the National Academy of Sciences). The research was conducted with the support of the Korea Institute of Energy Technology Evaluation and Planning and using the equipment and facilities of the UNIST Research Support Center.