KTU Researchers Develop Advanced Indoor Solar Cells to Optimize Light Energy Use

KTU Researchers Develop Advanced Indoor Solar Cells to Optimize Light Energy Use

by Robert Schreiber

Berlin, Germany (SPX) Jul 29, 2024

Scientists at Kaunas University of Technology (KTU) in Lithuania have created new materials that significantly enhance the efficiency of solar cells for indoor applications. These photovoltaic cells, which can be integrated into various electronic devices, generate electricity even in low-light environments.

The rising consumption of oil and gas has led to an increase in atmospheric temperatures, contributing to global climate change, now referred to as a climate crisis. To address this issue, renewable and environmentally friendly energy sources like wind, water, and solar power are being prioritized.

“Wind and hydro energy are constrained by high costs and location dependency, while solar energy is flexible, efficient and relatively inexpensive. However, the energy from indoor light sources and natural light entering through windows is lost every day,” says Juozas Vidas Grazulevicius, Professor at the KTU Faculty of Chemical Technology and Head of the Chemistry of Materials research group.

According to Professor Grazulevicius, indoor photovoltaics can solve this issue by generating electricity even in low-intensity light conditions.

A Growing Market for Efficient Indoor Solar Cells

“Perovskite photovoltaic cells for indoor use can be integrated into mobile phones, pocket flashlights, and other electronic devices; they can generate electricity under artificial light. Using Internet of Things (IoT) technologies, this electricity can be used to efficiently regulate the operation of devices and optimise energy consumption,” says Dr. Asta Dabuliene, Senior Researcher at the Chemistry of Materials research group, KTU.

The rapid development of IoT technologies has significantly expanded the market for indoor photovoltaic cells. High-performance, cost-effective, and versatile indoor PV cells are essential to meet this demand.

Dr. Dabuliene has synthesized a series of new efficient hole-transporting thiazol[5,4-d]thiazole derivatives for indoor perovskite photovoltaic cells. These layers selectively transport holes (positive charge carriers) while blocking electrons (negative charge carriers), reducing recombination losses and improving the overall efficiency of the solar cell.

“An ideal hole transporting semiconductor for these applications would possess high hole mobility and good energy level alignment with those of adjacent layers,” explains Dr. Dabuliene.

A thiazol[5,4-d]thiazole derivative containing a triphenylamine donor fragment, synthesized by Dr. Dabuliene, was used by researchers at Ming Chi University of Technology in Taiwan to develop perovskite solar cells for indoor use. The KTU-developed organic semiconductor enabled the cells to achieve a power conversion efficiency of 37.0% under 3000 K LED (1000 lx) illumination. The studies highlighted the great potential of thiazol[5,4-d]thiazole derivatives in enhancing the efficiency of perovskite solar cells.

International Collaboration Fuels Innovation

The innovation in indoor solar cells is the result of collaborative efforts by an international team of scientists. KTU’s Chemistry of Materials research group developed and synthesized organic semiconductors that efficiently transport positive charges and studied their properties. Theoretical studies of the new compounds were conducted by scientists from King Abdullah University of Science and Technology (Saudi Arabia). Researchers at Ming Chi University of Technology in Taiwan constructed and characterized the perovskite solar cells for indoor use.

Professor Grazulevicius emphasized the benefits of international collaboration: “This year, researchers from the Chemistry of Materials research group have won four European Horizon Programme projects. Moreover, we have received invitations from colleagues in the UK and Germany to collaborate in preparing yet another project proposal.”

He also noted that the Chemistry of Materials research group at KTU includes researchers from diverse countries such as Lithuania, Ukraine, India, Pakistan, Armenia, Egypt, and Nigeria. He believes that working in an international team brings varied perspectives and innovative solutions, though it requires navigating communication, cultural, and organizational challenges to achieve common goals.

“Different cultures and experiences help to generate new ideas and innovative solutions, and each team member brings unique knowledge and skills that enrich the overall range of competencies. Working with people who speak different languages allows us to improve international communication and promote language skills, while different working cultures promote greater flexibility and adaptability to different situations,” says Prof. Grazulevicius.

Research Report:Enhancement of Efficiency of Perovskite Solar Cells with Hole-Selective Layers of Rationally Designed Thiazolo[5,4-d]thiazole Derivatives