Recently, researchers of the Strong Magnetic Field Science Center of the Chinese Academy of Sciences' Hefei Institute of Material Science have adopted a strong magnetic field induction method to successfully realize the structural regulation of new high-performance semiconducting polymer films and significantly improve their charge transfer capabilities. The relevant research results are published in academic journals. Advanced Functional Materials published online. Effective control of structural characteristics such as molecular orientation, stacking, and crystallinity in organic semiconductor thin films plays a key role in realizing high-performance field effect transistors (OFETs) and solar cells. Organic molecules (especially pi conjugated molecules) have a strong susceptibility to magnetic susceptibility, making the molecular magnetic energy strongly dependent on the orientation between the molecular axis and the external magnetic field. A strong magnetic field can be used to control the alignment and orientation of the molecules and the growth mode during the growth of the material, and thus can be a clean, universal means of controlling the structure and properties of the material. At present, many types of liquid crystal materials, some simple small molecules and block polymer materials have been oriented and grown in a strong magnetic field. However, for conjugated molecules and polymer semiconductors with strong intermolecular interactions and high degree of structural order, strong magnetic field-induced growth and structural regulation are extremely difficult, and these materials generally have high carrier mobility and excellent electrooptic characteristics. Zhang Fapei, Research Fellow at the Strong Magnetic Field Science Center, teamed up with the researcher Dai Jianming of the Hefei Institute of Solid State Physics to solve the problem of strong magnetic field-induced growth and structural regulation of the above organic semiconductor thin films. By developing a new in-situ solution coating method under a strong magnetic field, a large-area macroscopically preferred orientation structure of crystalline and semi-crystalline polymer semiconductor thin films has been realized for the first time in the world. Through comprehensive micro-structure measurements, it was found that strong magnetic induction leads to a highly-oriented polymer chain of the novel high-performance polymer P (NDI2OD-T2) oriented along the magnetic field. They observed changes in the degree of orientation and degree of order of P(NDI2OD-T2) films grown in different organic solvents. It was found that the strong interaction between the molecular aggregates present in the polymer solution and the magnetic field induces and determines magnetism. In the process of orientation growth, a mechanism model of magnetic orientation growth of thin films was proposed. The researchers also effectively controlled the spatial orientation of the conjugate plane of the molecular skeleton in the thin film through a novel time-modulated magnetic field technique, significantly improving the face-on stacking along the normal of the film surface between P(NDI2OD-T2) molecules. Degree of order. The OFET device was grown using a thin film grown with a strong magnetic field, and it was found that the strong magnetically induced orientation can significantly increase the carrier mobility (up to 4 times) of the polymer semiconductor and generate strong carrier mobility anisotropy. P(NDI2OD-T2) is a typical "donor-acceptor" type polymer. This type of new polymer is one of the most important materials in organic electronics at present. The above work provides a new way to explore further improvement of its photoelectric properties. The important clues also provide instructive roles in deepening the understanding of the dynamic mechanism of organic magnetic material-induced growth and the intrinsic relationship between organic film structure and performance. The study was supported by the Chinese Academy of Sciences "Hundred Talent Plan" project and the National Natural Science Foundation project. 2'' 3'' Led Working Light,Led Autolamps Work Lights,Led Work Light For Car,Work Light Car CHANGZHOU CLD AUTO ELECTRICAL CO.,LTD , https://www.cld-leds.com
Hefei Institute of Magnetic Field-induced Organic Semiconductor Growth Research Progress