Discover how this innovation addresses the sustainability challenge and paves the way for wood-based solar cells, offering efficient, affordable, and environmentally conscious energy solutions.
Researchers at Linköping University and the Royal Institute of Technology (KTH) have unveiled a promising advancement in the field of organic solar cells, harnessing the power of lignin, one of nature’s most abundant organic materials. Published in the prestigious journal Advanced Materials, this study demonstrates the potential of untreated kraft lignin to enhance the environmental friendliness and reliability of organic solar cells.
While sunlight stands out as a prominent source of sustainable energy, traditional silicon-based solar cells, although efficient, are marred by energy-intensive and complex manufacturing processes, often involving hazardous chemicals. In response, organic solar cells have emerged as a focal point in research due to their low production costs, lightweight, flexibility, and versatility in applications such as indoor usage and wearable electronics. However, a significant drawback of organic solar cells is their reliance on plastics or oil-derived polymers, hindering their environmental sustainability.
To address this challenge, scientists from Linköping University and KTH have developed an organic solar cell featuring a component of the electron transport layer derived from kraft lignin, extracted directly from wood pulp. While the current iteration incorporates only a small fraction of lignin, the long-term objective is to create solar cells predominantly composed of wood-based materials. Professor Mats Fahlman of the Laboratory of Organic Electronics (LOE) at Linköping University emphasizes the mission to produce efficient, cost-effective, and eco-friendly solar cells. He envisions a future where oil-based materials are substituted with sustainable wood-based alternatives.
Previous research had explored chemically modified wood-based materials to enhance the stability of organic and perovskite solar cells. In this study, the researchers opted for “raw” kraft lignin, sourced directly from wood in paper manufacturing processes. They identified the ideal molecular composition of lignin for this purpose. Qilun Zhang, Principal Research Engineer at LOE, explains the incorporation of kraft lignin into the cathode interface layer, which significantly enhanced the solar cell’s stability. The unique bonding properties of kraft lignin, forming numerous hydrogen bonds, played a pivotal role in bolstering the solar cell’s structural integrity. Organic solar cells have already found applications, primarily indoors and in low-energy devices where they can replace batteries. Professor Fahlman believes that this breakthrough represents the first step toward wider adoption of organic solar cells, paving the way for larger-scale energy generation. Utilizing wood materials in their construction holds the promise of making the entire solar cell ecosystem more environmentally friendly.
While organic solar cells may not match the efficiency of their counterparts, their non-toxicity, sustainability, and affordability make them an attractive choice. With efficiency levels of 15%-20%, they prove more than adequate for the majority of applications, according to Fahlman. This groundbreaking research underscores the potential for lignin-powered solar cells to revolutionise the green energy landscape.
