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arXiv · 1904.07573

Plasmon Soft Mode in an Organic-Inorganic Hybrid Perovskite

Jiyu Tian·Karuna Kara Mishra·Eli Zysman-Colman·Finlay D. Morrison·Ram S. Katiyar·James F. Scott
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Abstract

We report inelastic light scattering from underdamped plasmons in azetidinium lead bromide (AzPbBr3). The plasmons are very strongly temperature dependent and serve as a soft mode for the semiconductor-insulator phase transition near TC {\guillemotright} 150 K, demonstrating a continuous decrease in hole concentration np(T) by at least a factor of four and implying a nearly tricritical transition. The plasmon frequency and linewidth agree with independent measurements, and the impedance analysis reveals a frequency dependence (modelled by a constant phase element, CPE) that can be identified as due to electron-phonon coupling. The dependence of plasmon frequency upon (TC-T) is analogous to that for magnons in magnetic insulators or soft transverse optical phonons in ferroelectrics and ferroelastics, or for phasons in incommensurately modulated insulators.

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Jiyu Tian, Karuna Kara Mishra, Eli Zysman-Colman, Finlay D. Morrison, Ram S. Katiyar, James F. Scott. 2019-04-16. Plasmon Soft Mode in an Organic-Inorganic Hybrid Perovskite. https://arxiv.org/abs/1904.07573

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