Beijing Institute of Technology has made significant progress in the study of ultrafast carrier dynamics in optoelectronic functional crystals

Recently, teachers and students from the Institute of Solid State Laser and Ultrafast Photonics at the School of Physics and Optoelectronic Engineering have made significant progress in the study of ultrafast carrier dynamics in optoelectronic functional crystals. The related research results are titled "Anisotropic carrier dynamics and laser fabricated luminosity patterns on oriented single crystal perovskite wafers" and published online in the international authoritative journal Nature Communications, The research results are of great significance for promoting the practical application process of functional crystals in the field of optoelectronics.

The first author of the paper is Beijing University of Technology, with Ge Chao, an assistant researcher at the School of Physics and Optoelectronic Engineering, and Li Yachao, a doctoral student, as co first authors. Ge Chao, an assistant researcher at Beijing University of Technology, and Song Haiying, an associate researcher, are co corresponding authors. Professor Zhang Wenkai from Beijing Normal University and Professor Liu Yang from Shandong University are also co corresponding authors. This study has been supported by projects such as the National Natural Science Foundation of China and the Beijing Municipal Education Commission Research Program.

In recent years, perovskite materials and their applications in the field of optoelectronics have attracted widespread attention. However, a deep understanding of their anisotropic behavior in ultrafast carrier dynamics is still insufficient. To compensate for this deficiency, the research team, based on high-quality MAPbBr3 single crystal wafers with different orientations, for the first time revealed the polarization of photo excited charge carriers within crystal planes with different orientations and the anisotropic dynamic evolution between crystal planes at the picosecond time scale. This discovery provides a deeper understanding of the relaxation pathways of ultrafast charge carriers from a crystallographic perspective, which is of great significance for exploring and expanding the applications of perovskite single crystals in the field of ultrafast optoelectronics, such as light modulators, high-speed polarization sensors, and ballistic transistors.

In addition, by using femtosecond laser two-photon processing technology, the research team successfully prepared three orders of magnitude fluorescence enhanced luminescent patterns. An in-depth analysis of the fluorescence enhancement mechanism from the perspectives of multidimensional space (bulk and micro/nanoscale) and time (steady-state and transient) provides a convenient top-down strategy for improving the photoluminescence intensity of bulk crystals. This study provides a profound understanding of the ultrafast carrier dynamics of MAPbBr3 from a crystallographic perspective, with the hope of providing more guidance for the orientation selection and utilization of perovskite hot carriers in optoelectronics in the future.

The dynamic evolution of photo excited charge carriers on the (100), (110), and (111) crystal planes of MAPbBr3 and the mechanism of femtosecond laser-induced fluorescence enhancement.

Source: OFweek