Recently, Guo Xin, a researcher at the Dalian Institute of Chemical Physics, Chinese Academy of Sciences, and Li Can, a member of the Chinese Academy of Sciences, have made new progress in the development of hole transport materials for perovskite solar cells. The relevant research results are published in the German Applied Chemistry (Angew. Chem Int. Ed.), and was selected as a VIP (Very Important Paper) paper.
Organic-inorganic hybrid perovskite solar cells have attracted much attention due to their high photoelectric conversion efficiency. Among them, hole transport materials (HTM) play an important role in improving device efficiency. The most widely used HTM is Sprio-OMeTAD. However, the symmetry of the molecule is high, and it is easy to crystallize, resulting in poor film stability and pinhole defects, which not only reduces the stability of the device, but also is not suitable for the preparation of large-area devices, which greatly limits its in calcium. Application in titanium ore solar cells.
In order to solve the above problems of Sprio-OMeTAD, based on the previous work (Nano Energy, Small, Solar RRL), the team based on the idea of 'reducing molecular symmetry and improving film morphology stability' from the original Sprio-OMeTAD kernel 'Cropping' a low-symmetry new spiro-nucleus, a snail, with a conjugated carbazole branch unit, successfully synthesizes a novel hole transport molecule, Spiro-I. Compared to the quasi-spherical Sprio-OMeTAD, the new molecule is presented. V-type structure and lower molecular symmetry, so the crystallization tendency of the molecule is effectively suppressed, and it is easier to form a pinhole-free high-quality film. Using Spiro-I as HTM to prepare perovskite solar cells, in large-area devices and The performance of the device is superior to that of the classic material Sprio-OMeTAD. In addition, the molecular synthesis cost is lower, and the amount of use in the device processing is small, which is beneficial to reduce the overall cost of the battery. This work is efficient, stable, and low in preparation. The cost of perovskite solar cells provides new hole transport materials and also provides new ideas for the molecular design of hole transport materials, which will help promote the further development of perovskite solar cells.
In addition, the team has been working on the carrier transport layer of the new photovoltaic device and its interface modification. In addition to the hole transport materials of the perovskite solar cell developed this time, they also reported the electrons of various organic solar cells. The hole transports the material and achieves excellent device properties (J. Mater. Chem. A, J. Mater. Chem. A, Org. Electron., J. Mater. Chem. A, ACS Appl. Mater. Interfaces). These work will contribute to the further development of the key material systems required for the new photovoltaic technology with independent intellectual property rights in Dalian.
The above research work was funded by the 'Thousand Talents Program' youth project, the National Natural Science Foundation, two fusion funds, and a postdoctoral fund.
