Halide perovskite solar cells have in recent years emerged as a potential alternative to silicon-based photovoltaics due to their outstanding performance, having reached energy conversion efficiency comparable to the currently available silicon counterparts in less than a decade of research. Therefore, in addition to vast academic interest, industries are paying close attention to the development of perovskite-based photovoltaics. However, there are still several key obstacles to be addressed before moving towards their commercial exploitation, relating to, e.g., toxicity, stability, and cost-efficiency.
The performance of perovskite solar cells is strongly influenced by its constituents, in particular the charge-transport (electrons or holes) layers that are needed to extract the charges from perovskite and transport them to the respective electrodes, while simultaneously preventing the direct contact between the perovskite and the metal contact. The currently used hole-transport materials (HTMs) suffer from several disadvantages such as extremely high-cost (over 400 $/g), poor stability, complex fabrication, and the use of toxic precursors. Thus, there is a crucial demand for the development of alternative low-cost HTMs and to ensure their sustainable industrial scalability.
The design and development of low-cost and high-performance HTMs is a hot topic in perovskite research and, consequently, engineering novel molecular designs is extremely challenging. In his doctoral dissertation, Jagadish Salunke contributed to the development of low-cost and environmentally friendly organic HTMs for perovskite solar cells. In particular, Salunke focused on the design, synthesis, and application of phenothiazine- and pyrene-core organic HTMs made by using eco-friendly synthesis processes. His designs enabled a significant cost reduction down to ~10 $/g and paved the way towards stable and, upon further optimization, high-performing perovskite solar cells.
Jagadish conducted his research within the Faculty of Engineering and Natural Sciences, in collaboration with an extensive national and international collaboration network. Particularly important was the tight collaboration with Associate Professor Paola Vivo and the Hybrid Solar Cell team that she leads.
“It was very exciting to design and develop novel organic small molecular HTMs for perovskite solar cells keeping the long-term goals of low-cost, high performance, high stability, and minimal environmental impact in mind. Those goals were still inconceivable during the initial period of my doctoral thesis work. I was constantly on a steep learning curve for both extending my know-how and my career goals, having to catch up with rapidly progressing research topics and to grow as an independent researcher at the same time. Indeed, the whole process was undeniably intriguing,” Jagadish mentions.
Jagadish Salunke’s doctoral research has been conducted thanks to the support of Fortum Foundation (Grant 201700234 & 201800260), Finnish Foundation for Technology Promotion, Emil Aaltonen Foundation, and Academy of Finland.
The doctoral dissertation of MSc (Organic Chemistry) Jagadish Salunke in the field of Chemistry, titled Low-cost phenothiazine- and pyrene-based hole-transporting materials for halide perovskite solar cells will be publicly examined in Faculty of Engineering and Natural Sciences, Tampere University at 12 o’clock on Friday, 15th of January 2021 in a public online defense. The opponent will be Dr. Raquel Galian from University of Valencia (Spain) and the Custos will be Professor Arri Priimägi.
The dissertation is available online at http://urn.fi/URN:ISBN:978-952-03-1846-8
Photo: Lina Salunke