Proton Migration in Hybrid Lead Iodide Perovskites: From Classical Hopping to Deep Quantum Tunneling.
Proton Migration in Hybrid Lead Iodide Perovskites: From Classical Hopping to Deep Quantum Tunneling.
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混合碘化铅钙钛矿中的质子迁移：从经典跳跃到深量子隧道
DOI：
10.1021/acs.jpclett.8b02929
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发表时间：
2018
影响因子：
5.7
通讯作者：
Li Xin Zheng
中科院分区：
文献类型：
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作者：
Feng Yexin;Zhao Yicheng;Zhou Wen Ke;Li Qi;Saidi Wissam A;Zhao Qing;Li Xin Zheng
有机-无机卤化物钙钛矿（OIHP）在太阳能电池领域显示出巨大的潜力，但其电流-电压滞后和长期不稳定性等问题严重阻碍了其应用。离子迁移被认为是相关的。但原子论的细节仍然不清楚。在这里，我们研究了迁移的离子在CH 3 NH3 PbI 3（MAPbI 3）在不同的温度（T的），使用相结合的实验和第一原理理论方法。碘离子的经典跳跃是中等温度下的主要迁移机制。低于270 K时，离子迁移的动力学常数仍然表现出Arrenhius依赖性，但低得多的活化能归因于H+的迁移。在140 ~ 180 K之间发生了从经典到量子的渐变。低于1080 K时，动力学常数与T无关，表明H+的深量子隧穿占据了主导地位。本研究为MAPbI 3中H+s的迁移提供了直接的实验证据，并证实了它们的量子性质。
The organic–inorganic halide perovskites (OIHPs) have shown enormous potential for solar cells, while problems like the current–voltage hysteresis and the long-term instability have seriously hindered their applications. Ion migrations are believed to be relevant. But the atomistic details still remain unclear. Here we study the migrations of ions in CH3NH3PbI3(MAPbI3) at varying temperatures (T’s), using combined experimental and first-principle theoretical methods. Classical hopping of the iodide ions is the main migration mechanism at moderateT’s. Below ∼270 K, the kinetic constant for ionic migration still shows an Arrenhius dependency, but the much lower activation energy is attributed to the migration of H+. A gradual classical-to-quantum transition takes place between ∼140 and ∼80 K. Below ∼80 K, the kinetic constant becomesT-independent, suggesting that deep quantum tunneling of H+takes over. This study gives direct experimental evidence for the migrations of H+s in MAPbI3and confirms their quantum nature.