A team of researchers from DGIST, Incheon National University, and the Department of Electronic Materials Engineering collaborated to enhance the performance of kesterite (CZTSSe) thin-film solar cells. CZTSSe cells are considered a promising solar cell technology due to their resource abundance, low cost, and eco-friendly nature. However, they have low efficiency and high current losses that hinder commercialization. To address these challenges, the research team developed a new method of doping silver (Ag) into solar cells to suppress defects, promote crystal growth, and increase efficiency significantly.
By doping the solar cell precursor with Ag, the team was able to prevent the loss of tin, improve material mixing at low temperatures, and facilitate larger and faster crystal growth. This led to a reduction in defects and enhancements in solar cell performance. The team systematically analyzed how the location of Ag doping in the precursor affects defects and electron-hole recombination in the solar cell, demonstrating the significant performance improvements that Ag can offer by preventing Sn loss and maximizing defect suppression effects.
The researchers also discovered that incorrect placement of Ag doping can interfere with the formation of Zn and Cu alloy, resulting in the creation of defect clusters that increase electron-hole recombination losses and degrade performance. This insight highlights the importance of precise Ag doping in improving solar cell efficiency. The team found that the liquid material formed by Ag doping promotes crystal growth, leading to enhanced density and crystallinity of the absorber layer, improved energy band structure, reduced defects, and smoother charge transport in the cell, all contributing to high-performance solar cells at low cost.
The study provides crucial insights into the design of silver-doped precursor structures for enhancing solar cell efficiency. Senior researcher Kee-jeong Yang emphasized the importance of understanding the role of silver in suppressing tin loss and improving defects to advance solar cell technologies. The research was supported by the Ministry of Science and ICT’s Source Technology Development program and the Future-Leading Specialization Research program, and the findings were published in the Energy & Environmental Energy journal, a leading international publication in the energy field.
Overall, the research collaboration between DGIST, Incheon National University, and the Department of Electronic Materials Engineering has made significant advancements in enhancing the performance of kesterite thin-film solar cells through innovative silver doping techniques. The study’s findings provide a roadmap for improving solar cell efficiency, reducing defects, and ultimately paving the way for the production of high-performance solar cells at low cost. This research has the potential to drive advancements in solar cell technology and contribute to the development of sustainable and efficient energy solutions for the future.