Hybrid organolead perovskites (HOP) have started to establish themselves in the field of photovoltaics, mainly due to their great optoelectronic properties and steadily improving solar cell efficiency. Study of the lattice dynamics is key in understanding the electron-phonon interactions at play, responsible for such properties. Here, we investigate, via neutron and Raman spectroscopies, the optical phonon spectrum of four different HOP single crystals: MAPbBr₃, FAPbBr₃, MAPbI₃, and α-FAPbI₃. Low temperature spectra reveal weakly dispersive optical phonons, at energies as low as 2-5 meV, which seem to be the origin of the limit of the charge carriers mobilities in these materials. The temperature dependence of our neutron spectra shows as well a significant anharmonic behaviour, resulting in optical phonon overdamping at temperatures as low as 80 K, questionning the validity of the quasi-particle picture for the low energy optical modes at room temperature where the solar cells operate.

杂化有机铅钙钛矿（HOP）已开始在光伏领域确立地位，这主要是由于其出色的光电性能并稳定地提高了太阳能电池的效率。晶格动力学的研究对于理解造成这种性质的电子-声子相互作用至关重要。在这里，我们通过中子和拉曼光谱研究了四种不同的HOP单晶的光学声子光谱：MAPbBr ₃，FAPbBr ₃，MAPbI ₃和α- FAPbI ₃。低温光谱显示出能量低至2-5 meV的弱色散光子，这似乎是这些材料中载流子迁移率极限的起源。我们的中子光谱的温度依赖性还显示出显着的非谐行为，从而导致在低至80 K的温度下光子发生声子过阻尼，从而质疑准粒子图对于太阳能电池在室温下的低能光学模式的有效性操作。