Polarization and Dielectric Study of Methylammonium Lead Iodide Thin Film to Reveal its Nonferroelectric Nature under Solar Cell Operating Conditions
Polarization and Dielectric Study of Methylammonium Lead Iodide Thin Film to Reveal its Nonferroelectric Nature under Solar Cell Operating Conditions
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DOI：
10.1021/acsenergylett.6b00093
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发表时间：
2016-07-01
影响因子：
22
通讯作者：
Fan, Zhaoyang
中科院分区：
文献类型：
--
作者：
Hoque, Md Nadim Ferdous;Yang, Mengjin;Fan, Zhaoyang
研究人员一直在争论具有钙钛矿晶体结构的碘化铅甲基铵（MAPbI(3)）是否具有铁电性，从而导致了混合钙钛矿太阳能电池（PSCs）中常见的电流电压滞后现象。我们深入研究了温度相关的极化、介电和阻抗谱，发现在正常工作条件下，MAPbI(3)薄膜中没有铁电效应的证据。因此，这种效应不会导致psc的迟滞，而观察到的离子迁移的大组成部分可能起关键作用。我们基于温度的极化和介电研究发现，MAPbI3在45℃以下和45℃以上表现出不同的电行为，表明在该温度附近存在相变。特别是，我们报道了两相离子迁移的活化能和MAPbI的温度相关介电常数(3)。该研究有助于理解杂化钙钛矿的性能。
Researchers have debated whether methylammonium lead iodide (MAPbI(3)), with a perovskite crystal structure, is ferroelectric and therefore contributes to the current voltage hysteresis commonly observed in hybrid perovskite solar cells (PSCs). We thoroughly investigated temperature-dependent polarization, dielectric, and impedance spectroscopies, and we found no evidence of ferroelectric effect in a MAPbI(3) thin film at normal operating conditions. Therefore, the effect does not contribute to the hysteresis in PSCs, whereas the large component of ionic migration observed may play a critical role. Our temperature-based polarization and dielectric studies find that MAPbI3 exhibits different electrical behaviors below and above ca. 45 degrees C, suggesting a phase transition around this temperature. In particular, we report the activation energies of ionic migration for the two phases and temperature-dependent permittivity of MAPbI(3). This study contributes to the understanding performance of hybrid perovskites.