Magnetic field effects in hybrid perovskite devices
Magnetic field effects in hybrid perovskite devices
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DOI：
10.1038/nphys3277
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发表时间：
2015-03
期刊：
影响因子：
19.6
通讯作者：
Chuang Zhang;Dali Sun;Chuanxiang Sheng;Y. Zhai;Kamil Mielczarek;A. Zakhidov;Z. Vardeny
中科院分区：
文献类型：
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作者：
Chuang Zhang;Dali Sun;Chuanxiang Sheng;Y. Zhai;Kamil Mielczarek;A. Zakhidov;Z. Vardeny
磁场效应已经成为研究有机半导体中载流子动力学的一个成功工具，因为这些材料中弱的自旋-轨道耦合引起长的自旋弛豫时间。由于有机-无机杂化钙钛矿中的自旋-轨道耦合很强，这是用于光伏和发光应用的有前途的材料，因此预期磁场效应在这些光电器件中可以忽略不计。我们在混合钙钛矿器件和薄膜中测量了显着的磁光电流，磁致发光和磁光致发光响应，其中振幅和形状通过电子空穴寿命相互关联，这取决于钙钛矿薄膜的形态。我们将这些响应归因于磁场诱导的具有不同g因子的光生电子-空穴对的自旋混合-Δ g模型。我们验证了这个模型，通过测量大的Δg（Δ 0.65）使用场诱导圆偏振光致发光，和电子空穴对寿命使用皮秒泵浦探测光谱。
Magnetic field effects have been a successful tool for studying carrier dynamics in organic semiconductors as the weak spin–orbit coupling in these materials gives rise to long spin relaxation times. As the spin–orbit coupling is strong in organic–inorganic hybrid perovskites, which are promising materials for photovoltaic and light-emitting applications, magnetic field effects are expected to be negligible in these optoelectronic devices. We measured significant magneto-photocurrent, magneto-electroluminescence and magneto-photoluminescence responses in hybrid perovskite devices and thin films, where the amplitude and shape are correlated to each other through the electron–hole lifetime, which depends on the perovskite film morphology. We attribute these responses to magnetic-field-induced spin-mixing of the photogenerated electron–hole pairs with differentg-factors—the Δgmodel. We validate this model by measuring large Δg(∼ 0.65) using field-induced circularly polarized photoluminescence, and electron–hole pair lifetime using picosecond pump–probe spectroscopy.