Unraveling the hysteretic behavior at double cations-double halides perovskite - electrode interfaces
Unraveling the hysteretic behavior at double cations-double halides perovskite - electrode interfaces
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DOI：
10.1016/j.nanoen.2021.106428
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发表时间：
2021-11
期刊：
影响因子：
17.6
通讯作者：
Dohyung Kim;Yongtao Liu;A. Ievlev;Kate Higgins;O. Ovchinnikova;J. Yun;J. Seidel;Sergei V. Kalinin;M. Ahmadi
中科院分区：
文献类型：
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作者：
Dohyung Kim;Yongtao Liu;A. Ievlev;Kate Higgins;O. Ovchinnikova;J. Yun;J. Seidel;Sergei V. Kalinin;M. Ahmadi
尽管在光伏应用背景下对金属卤化物钙钛矿（MHP）进行了十多年的研究，但对与电流-电压（I-V）滞后行为相关的电子和离子过程的性质的理解仍然有限。在这里，我们探索的滞后行为（FAPbI 3）0.85（MAPbBr 3）0.15钙钛矿设备与横向Cr电极，通过应用一阶反转曲线（FORC）的偏压波形在I-V，开尔文探针力显微镜（KPFM）测量，并在原位化学成像的时间分辨飞行时间二次离子质谱（tr-ToF-西姆斯）。在黑暗中，我们揭示了显着的滞后行为的电荷动力学在场外通过探测随时间变化的电流和接触电位差（CPD）。在光照下，瞬态和滞后行为显着减少。tr-ToF-西姆斯的结果表明，滞后行为与Br-离子在界面处的积累密切相关。此外，低迁移率的MA+离子导致瞬态行为，并有助于滞后现象。结果表明，Pb 2+离子可以在界面处被还原，由于在电荷注入和光生电荷的存在下与电极的电化学反应。这些与电荷动力学、离子迁移和界面电化学反应相关的滞后行为对于进一步提高MHP光致发光和光电子学的性能和稳定性至关重要。
Despite over a decade of research on metal halide perovskites (MHPs) in the context of photovoltaic applications, understanding the nature of electronic and ionic processes associated with current-voltage (I-V) hysteretic behavior has been limited. Here, we explore the hysteretic behavior in (FAPbI3)0.85(MAPbBr3)0.15perovskite devices with lateral Cr electrodes by applying first order reversal curve (FORC) bias waveform inI-V, Kelvin probe force microscopy (KPFM) measurements, and in-situ chemical imaging by time-resolved time-of-flight secondary ion mass spectrometry (tr-ToF-SIMS). In dark, we reveal pronounced hysteretic behaviors of charge dynamics in the off-field by probing time-dependent current and contact potential difference (CPD). Under illumination, transient and hysteretic behaviors are significantly reduced. The tr-ToF-SIMS results reveal that the hysteretic behaviors are strongly associated with accumulation of Br-ions at the interfaces. In addition, the low mobility MA+ions result in transient behavior and contribute to the hysteretic phenomena. It was shown that Pb2+ions can be reduced at the interfaces due to electrochemical reactions with the electrode in the presence of charge injection and photogenerated charges. These hysteretic behaviors associated with charge dynamics, ion migration, and interfacial electrochemical reaction are critical to further improve the performance and stability of MHPs photovoltaics and optoelectronics.