Recently, North China Electric Power University Dai Songyuan team / Xi’an Jiaotong University Yang Champion team / Lausanne Federal Polytechnic University M. K. Nazeeruddin’s team et al. synthesized diamond-shaped single crystal TiO2 nanoparticles by one-step solvothermal method and used it for the mesoporous charge transfer layer in perovskite solar cells, which effectively reduced the photoelectric loss of the device and improved the efficiency of small-area batteries (24.05%) and the filling factor (84.7%).
On April 21, 2022, the study was published in Nature Nanotechnology under the title “Single-crystalline TiO2 nanoparticles for stable and efficient perovskite modules.” The first authors of the paper are Ding Yong and Ding Bin, and the corresponding authors are Yang Guanjun, Dai Songyuan, Paul. J. Dyson、Mohammad Khaja Nazeeruddin。
After more than 10 years of rapid development, organic-inorganic hybrid perovskite solar cells have a certified efficiency of up to 25.7% comparable to commercial crystalline silicon solar cells. However, there is still a big gap between the efficiency of the component and the small size of the laboratory battery, mainly due to the high resistance of the charge transfer layer, the charge transfer layer/perovskite interface, and the photoelectric loss caused by the internal defects of the large perovskite film. Therefore, how to prepare high-quality charge transfer layers and perovskite films and reduce intralayer and interfacial losses is a major challenge at present.
Dai Songyuan Team of North China Electric Power University/Yang Champion Team of Xi’an Jiaotong University/M. Federal Polytechnic University of Lausanne K. Nazeeruddin’s team et al. synthesized diamond-shaped single crystal TiO2 nanoparticles by one-step solvothermal method, and used it for the mesoporous charge transport layer in perovskite solar cells, with the help of the high crystallinity, low density defect state, high conductivity, high lattice matching degree of TiO2 nanoling and its high affinity with perovskites, effectively reducing the photoelectric loss of the device, thereby improving the efficiency of small-area batteries (24.05%) and the filling factor (84.7%).
In view of the current wide use of spin coating and anti-solvent technology in laboratories to prepare perovskite absorbent layer, but in the process of solvent removal, the spin-off anti-solvent will cause pinholes and/or crack defects in large areas of perovskite films, directly inhibiting charge extraction and resulting in trap-state composites, limiting the large-area preparation of high-quality perovskite films. The authors’ team used the self-developed vacuum extraction method to prepare high-quality perovskite films, which is more suitable for batch preparation of large-area perovskite films. Accordingly, a large-area module with an effective area of 24 cm2 was prepared, and the certification efficiency reached 22.72%, which significantly narrowed the efficiency gap between large modules and small batteries.
The above research shows that the design of the diamond-shaped single crystal structure of the electron transport layer and the development of the pumping preparation method of the perovskite layer provide a new technical route for improving the efficiency of large-area modules and promoting the industrialization of perovskite photovoltaics. (Source: Science Network)
Related paper information:https://doi.org/10.1038/s41565-022-01108-1