Department of Materials Science and Engineering, Pohang University of Science and Technology (POSTECH) . Pohang, Gyungbuk 37673, Republic of Korea.
Department of Materials Science and Engineering, Seoul National University , 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Republic of Korea.
ACS Appl Mater Interfaces. 2017 Mar 29;9(12):10344-10348. doi: 10.1021/acsami.6b15694. Epub 2017 Mar 15.
We extracted the electronic disorder energy of the organic-inorganic lead-halide hybrid perovskite CHNHPbBr from temperature-dependent absorption data. We showed that the disorder at room temperature is ∼30 meV and is due to strong electron-phonon coupling with the longitudinal-optical mode of energy 16 meV. This mode can be attributed to longitudinal-optical phonons of the inorganic PbBr frame; this conclusion highlights the polaronic nature of electronic excitations in CHNHPbBr. We showed that structural disorder is of the same impact as thermal disorder. A temperature-dependence of the exciton binding energy was observed close to the orthorhombic-to-tetragonal phase-transition temperature.
我们从温度依赖的吸收数据中提取了有机-无机卤化铅钙钛矿 CHNHPbBr 的电子无序能。我们表明，室温下的无序度约为 30 毫电子伏特，这是由于与能量为 16 毫电子伏特的纵光学模式的强电子-声子耦合所致。该模式可以归因于无机 PbBr 框架的纵光学声子；这一结论突出了 CHNHPbBr 中电子激发的极化子性质。我们表明，结构无序与热无序具有相同的影响。在接近正交相到四方相转变温度的情况下，观察到激子束缚能的温度依赖性。
