Researchers at China's Wuhan University of Technology, Huazhong University of Science and Technology and Jinan Municipal Bureau of Industry and Information Technology have developed a novel playdough-like graphite putty as top electrode for perovskite solar devices. The electrode is malleable and so can form good contact with the hole-transporting layer and the conductive substrate at room temperature using a simple pressing technique, which facilitates the fabrication of both small-area devices and perovskite solar modules.
Carbon-based perovskite solar cells (C-PSCs) are promising candidates for large-scale photovoltaic applications due to their theoretical low cost and high stability. However, the fabrication of high-performance C-PSCs with large-area electrodes remains challenging. In their recent research, the team showed that corresponding small devices and modules can achieve efficiencies of 20.29% (∼0.15 cm2) and 16.01% (∼10 cm2), respectively. Moreover, they analyzed the limitations of the optical and electrical properties of this playdough-like graphite electrode on the device performance, suggesting a direction for further improvement of C-PSCs in the future.
The team explained that the soft and moldable playdough-like graphite (PG) putty used in the transferring electrode combines the highly deformable property of carbon paste and the solvent-free property of carbon film, which ensures its applicability in high-performance, large-area PSC devices. By a simple raw materials mixing and electrode preparation process, PG based top electrodes were shown to achieve respectable champion PCEs. Compared with standard Au electrode based small devices, the PG based ones exhibit similar performance and superior storage stability.
The scientists stated that the PG material and its process method integrate the advantages of printable electrode from low-temperature carbon paste and transferring electrode from prefabricated carbon film. Despite the shortcomings of PG electrode in terms of optical reflection and module conductivity relative to Au electrode, the low material cost, environmental sustainability, simple process, and easy scalability of the PG electrode make this technique highly promising for the industrialization of C-PSCs.
