化物变异对MAPbX3 (X = Cl, Br, 和 I) 中的阴离子动态的影响
Veerendra K Sharma1,2, Ashutosh Mohanty3,4, Victoria García Sakai5
1Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai, 400085, India.
Small (Weinheim an der Bergstrasse, Germany)
|July 7, 2025
概括
化 (MA) 酸在化矿中表现出不同的旋转动力学在不同的相和化组成. 与MAPbBr3和MAPbI3.3相比,MAPbCl3显示MA+旋转的激活能量较低.
科学领域:
- 材料科学 材料科学 材料科学
- 固态化学 固态化学
- 晶体学 晶体学是指结晶学.
背景情况:
- 甲基化甲基 (MAPbX3) 对于光电子应用至关重要.
- 了解离子动态是它们稳定性和性能的关键.
- 晶体相转换显著影响材料特性.
研究的目的:
- 为了研究在MAPbCl3.3.中甲基 (MA) 离子体的温度依赖的动态.
- 将这些动态与MAPbBr3和MAPbI3进行比较,以了解化物效应.
- 为了将离子运动与晶体相和结构扭曲相关联.
主要方法:
- 不弹性中子散射被用来探测阴子动态.
- 在各种晶体学阶段进行了温度依赖的测量.
- 计算了不同的旋转运动的激活能量.
主要成果:
- 确定了两种不同的MA+运动:在正交相 (16 meV) 中的三倍旋转和在四边形/立方相 (60 meV) 中的四倍旋转.
- 观察到离子旋转运动和化物组成 (I− > Br− > Cl−) 之间存在强烈的相关性.
- MAPbCl3在三倍旋转时表现出更广泛的起始温度,并在四角形到立方形相变时呈现出独特的弹性强度过渡.
结论:
- 与MAPbBr3和MAPbI3.3相比,MAPbCl3的八面体扭曲促进了离子重定位,导致较低的激活能量和开始温度.
- 化物离子半径直接影响MA+旋转上的硬质约束.
- 这项研究提供了关于化 Perowskites 的结构-动力学-属性关系的见解.
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