Thin-Film Single-Crystal Growth of Layered Materials and Fabrication of The Layered Superlattices by a Hot Wall Technique, and Their Optical Properties

本文采用热壁技术生长了PbI_2和BiI_3两种层状化合物的超薄单晶体，这两种化合物是重金属卤化物的代表。所谓的货车德瓦耳斯外延成为可能，通过采用层状材料作为衬底.这种方法的低温生长使生长高质量的薄单晶成为可能。用带边直接激子的低温吸收谱作为薄膜质量的探针。透射电子衍射和x射线结构分析证实了这一点，并发现激子谱对晶体质量特别是层错和多型体的质量敏感。因此，它成为可能，以获得一个最佳的厚度为观察的直接激子吸收光谱的膜。对于PbI_2，阐明了激子的内部结构 ...更多信息 这是自1960年成功地对强脉冲磁场光谱进行磁光研究以来一直未能解决的令人困惑的问题。同时，对激子-声子相互作用的新特征也有了新的认识。在BiI_3薄膜中，由于薄膜表面的高质量，在吸收测量中首次观察到了表面激子。详细的带边激子吸收光谱的分析成为可能，和新的方面的激子动力学被发现相关的激子-声子相互作用。首次成功地制备了PbI_2/BiI_3超晶格，并对其光学性质进行了研究，发现了新超晶格中激子的有趣特征。利用BiI_3势垒观察到PbI_2激子的量子尺寸效应。目前正利用高场磁光和高压研究该系统中激子的吸收和发光来研究其电能结构。少

A hot wall technique was applied to grow very thin single-crystals of the compound layered materials, PbI_2 and BiI_3, which are the subject of the recent intensive investigations as the representative of the heavy metal halides. The so- called van der Waals epitaxy became possible by employing the layered material as a substrate. The low temperature growth by this method made it possible to grow high quality thin single-crystals. The low temperature absorption spectra of the band-edge direct exciton were used as a probe of the quality of the film. This is confirmed by the transmission electron diffraction and x-ray structural analysis.It was revealed that the exciton spectra was sensitive to the crystal quality especially for the layer stacking faults and polytypes. Thus it became possible to obtain the films with an optimized thickness for the observation of the direct exciton absorption spectra. As for PbI_2, the inner structure of the exciton were clarified to give the answer for t … More he puzzling problem unsolved since 1960 by the successful magneto-optical investigation of the high pulse-magnetic-field spectroscopy. At the same time, new features concerning the exciton-phonon interaction were understood. In the case of BiI_3, the surface exciton was observed for the first time in the absorption measurement due to the high quality of the film surface. The detailed analysis of the band-edge exciton absorption spectra became possible, and new aspects of the exciton dynamics were found correlated to the exciton-phonon interaction. The superlattice PbI_2/BiI_3 were successfully fabricated for the first time by this technique, and the optical properties were investigated, showing interesting features of the exciton in the new superlattice. The quantum size effect was observed on the exciton of PbI_2 by the BiI_3 barrier potential. The electrical energy structure are now under investigation using high-field magneto-optical and high-pressure investigation on the absorption and luminescence of the exciton in this system. Less