Breakthrough: Researchers Unlock Secret to Enhancing Solar Cell Efficiency

A breakthrough in solar technology has been achieved through the successful identification of critical parameters that determine the performance and lifespan of halide perovskites. These next-generation photovoltaic materials have emerged as one of the most promising options for photovoltaic devices due to their unique crystal structure. The findings of this research have been published in the prestigious journal Science.

Assistant Professor LIN Yen-Hung, leading the research team from the Department of Electronic and Computer Engineering and the State Key Laboratory of Advanced Displays and Optoelectronics Technologies, focused on investigating various methods of passivation. Passivation is a chemical process that reduces defects or mitigates their impact in materials, thereby enhancing the performance and longevity of devices containing these materials. The team specifically explored the use of the “amino-silane” molecular family for passivating perovskite solar cells.

Prof. Lin highlighted the importance of passivation in improving the efficiency of perovskite solar cells over the past decade. However, he noted that routes leading to high efficiencies often do not significantly enhance long-term operational stability. For the first time, the research team demonstrated how different types of amines, such as primary, secondary, and tertiary, along with their combinations, can improve the surfaces of perovskite films where defects commonly occur.

By utilizing both “ex-situ” and “in-situ” methods to observe the interactions of molecules with perovskites, the team identified molecules that significantly increased the photoluminescence quantum yield (PLQY). This increase indicates fewer defects and higher quality in the materials. Prof. Lin emphasized the importance of this approach for the development of tandem solar cells, which can maximize the use of the solar spectrum by absorbing different parts of sunlight in each layer, ultimately leading to higher overall efficiency.

In their solar cell demonstration, the team fabricated devices of medium and large sizes, achieving low photovoltage loss across a broad range of bandgaps and maintaining high voltage output. Benchmarking against existing literature data, their results showed high efficiency in energy conversion, ranking among the best reported to date. Moreover, the study demonstrated remarkable operational stability for amino-silane passivated cells under standardized testing procedures, showcasing high efficiency and durability.

Prof. Lin highlighted that their treatment process not only enhances the efficiency and durability of perovskite solar cells but is also compatible with industrial-scale production. Drawing parallels to the widely used HMDS priming process in the semiconductor industry, he suggested that their new method could be seamlessly integrated into existing manufacturing processes, making it commercially viable and ready for large-scale application. The research team, including PhD student CAO Xue-Li and Dr. Fion YEUNG, collaborated with experts from Oxford University and the University of Sheffield to achieve these groundbreaking results.