Revolutionary Transparent Solar Cell Charges Smartphone

Researchers in Korea have made a significant breakthrough in solar cell technology by developing a transparent solar cell with back contacts that successfully powered a smartphone. The team at UNIST in Korea introduced a new type of transparent solar cell and module that boasts high efficiency and glass-like properties.

Professor Kwanyong Seo and his research team at the School of Energy and Chemical Engineering at UNIST devised an innovative ‘all-back-contact’ (ABC) design, which positions all the components of the solar cell on the back. The 16 cm² crystalline transparent solar cell module exhibits high efficiency levels ranging from 20% to 14.7% in transmittance, all while maintaining an aesthetic appeal similar to that of a single device.

The ABC design not only showcases high power conversion efficiency (PCE) in solar cells but also guarantees unobstructed visibility through transparent solar modules. Notably, the ABC–transparent c-Si solar cells achieved a peak PCE of 15.8% while maintaining an average visible transmittance of 20%. By seamlessly interconnecting the unit cells, the output voltage and power were systematically adjusted from 0.64 V and 15.8 mW (for a 1 cm2-sized unit cell) to 10.0 V and 235 mW for the 16 cm2-sized module.

The research team also introduced a groundbreaking seamless modularization technology that eliminates gaps between devices without relying on metal wires. This new method addresses the issue of damaging the aesthetics of transparent solar cells caused by the gaps between devices and opaque metal wires in the traditional modularization process.

Moreover, the team successfully demonstrated the capability of charging a smartphone using natural sunlight, highlighting the potential for utilizing the screen of small mobile devices as an energy source. Researcher Jeonghwan Park and Research Assistant Professor Kangmin Lee emphasized the significance of this advancement, stating, “This study fundamentally solved the aesthetic problem of the existing solar cell modularization method through the design of the new device structure. It presented the possibility that transparent silicon solar cells can be used in various industries such as small devices as well as buildings and automobile glass.”

Professor Seo expressed optimism about the future of transparent solar cell technology, stating, “We have opened a new path for modularization research, which is essential for the commercialization of transparent silicon solar cells. We plan to continue further research so that transparent solar cells can become a key technology in the eco-friendly future energy industry.” This groundbreaking development marks a significant step forward in the field of solar energy innovation.