Reported by: School of Materials Science and Engineering
Translated by: XU Jingxin
Edited by: Daniel Penistone
The research group of Professor Zhen Liang of the School of Materials Science and Engineering, as well as Professor Ren Wencai of the Institute of Metal Research of Chinese Academy of Sciences has made new progress in the exciton regulation of Supramoly or Van der Waals heterojunction of grapheme. The related results have been published in Advanced Functional Materials (Impact Factor 11.805), which has HIT as the only undersigned unit of communication.
The research uses heterojunction to regulate and control exciton behavior of semi-conductors, including the generation, transfer, separation, and recombination of exciton, which has particular value in the research of physical mechanisms and the application of photoelectric devices. Compared with traditional semi-conductive heterojunction, the Van der Waals heterojunction composed of two-dimensional materials does not need to meet the requirement of the lattice match through a new interface, and has a simpler preparation method, which is a perfect system of heterogeneous exciton behavior research.
Under the direction of Professor Zhen Liang and Professor Xu Chengyan, Doctor Li Yang constructed the monolayer Supramoly or Graphene heterojunction, and systematically studied the influences of the band alignment at the interface of Supramoly and the Graphene carrier concentration in Supramoly on the photoluminescence of heterojunction and exciton behavior. Through the regulation of grid bias, the range of intensity of the neutral and negative exciton of Supramoly can reach up to more than 200, and the binding energy of exciton has nearly 40-trillion-mev excursion. The research takes advantage of potential distribution model of the heterostructure devices and the First Principle in order to affirm that the exciton behavior of heterojunction is decided together by the Graphene carrier concentration in Supramoly and the contact barrier at the interface. Besides, through the introduction of self-assembly monolayer to control the contact barrier at the interface between Supramoly and Graphene, the controlling factors of heterojunction’s exciton behavior under diverse conditions of bias were learned. The research primarily illuminates the influence factor of the exciton behavior of the two-dimensional material, Van der Waals heterojunction, which is the foundation of designing new photoelectric devices.
The research obtains subsidies from the Natural Science Foundation of China, the Independent Subject of National Key Laboratory od Advanced Welding and Connection, the “Young Talent Funds” of HIT, and the “Cultivation Project of Basic Research Talents” (III)。
Link to the thesis：http://dx.doi.org/10.1002/adfm.201503131
