Dielectric confinement effect on excitons in PbI4 -based layered semiconductors

作者：Xindi Hong, Teruya Ishihara, Arto V Nurmikko · 发表于：Physical review. B, Condensed matter · 年份：1992 · DOI：10.1103/physrevb.45.6961 · 被引用次数：772 · 研究领域：Perovskite Materials and Applications、Inorganic Chemistry and Materials、Crystal Structures and Properties

By varying the dielectric environment in new ${\mathrm{PbI}}_{4}$-based layer-type perovskite compounds, we have demonstrated directly the contribution by dielectric confinement to the exciton binding energy in three such ``natural-quantum-well'' semiconductors. With different dielectric environment, exciton binding energies of 320, 220, and 170 meV have been observed, dominated by the dielectric confinement. In terms of the conventional size-related electronic confinement, two of the materials represent monolayer ${\mathrm{PbI}}_{4}$ quantum wells while the third corresponds to a bilayer case, with a corresponding reduction in the electronic confinement. From theory, including the dielectric confinement effect, the effective mass of the exciton in a ${\mathrm{PbI}}_{4}$-based dielectric quantum well has been determined to be 0.09${\mathit{m}}_{\mathit{e}}$; the corresponding quasi-two-dimensional exciton Bohr radii were 15.5, 17.0, and 20.5 \AA{} for the three cases, respectively.