Alvarez Agustin O, de Boer Jeroen J, Sonneveld Lars, Bleiji Yorick, Alarcón-Lladó Esther, Ehrler Bruno
AMOLF, Science Park 104, 1098 XG Amsterdam, The Netherlands.
van 't Hoff Institute for Molecular Sciences, Universiteit van Amsterdam, 1012 WX Amsterdam, The Netherlands.
ACS Energy Lett. 2025 Jul 24;10(8):3983-3992. doi: 10.1021/acsenergylett.5c01556. eCollection 2025 Aug 8.
Halide perovskite devices exhibit diverse current-voltage hysteresis behaviors, driven by distinct mechanisms that can enhance or hinder performance, making their understanding crucial. Among these, abrupt switching is particularly relevant for memristive operation and reverse-bias breakdown in solar cells. In this work, we identify four distinct hysteresis responses: capacitive, inductive, hysteresis-free, and abrupt switching. All four behaviors are clearly observed via cyclic voltammetry in a simple perovskite device with silver contacts. Real-time photoluminescence microscopy shows that continuous bias and illumination progressively modify the perovskite-electrode interface, transforming inductive into hysteresis-free behavior and supporting its interfacial origin. Further stress leads to filament formation, with abrupt switching occurring only when a filament bridges the electrodes, forming a reversible short circuit. This switching arises from dynamic contact at the filament-electrode interface. Conductive AFM and electron microscopy reveal that the filaments are highly conductive and composed of metallic silver. Transient and impedance measurements effectively differentiate the hysteresis modes. Similar responses are found in gold-contacted devices, though abrupt switching is restricted to nanometer-scale gaps between the electrodes, suggesting the formation of smaller, less stable filaments due to the lower reactivity of gold. These findings provide valuable insights for advancing switching and understanding hysteresis in perovskite-based devices.
卤化物钙钛矿器件表现出多种电流-电压滞后行为，其由不同的机制驱动，这些机制可增强或阻碍器件性能，因此对其进行理解至关重要。其中，突然开关对于忆阻操作和太阳能电池中的反向偏置击穿尤为重要。在这项工作中，我们识别出四种不同的滞后响应：电容性、电感性、无滞后和突然开关。通过循环伏安法在具有银接触的简单钙钛矿器件中清晰地观察到了所有这四种行为。实时光致发光显微镜表明，连续的偏置和光照会逐渐改变钙钛矿-电极界面，将电感性行为转变为无滞后行为，并支持其界面起源。进一步的应力会导致细丝形成，只有当细丝桥接电极形成可逆短路时才会发生突然开关。这种开关源于细丝-电极界面处的动态接触。导电原子力显微镜和电子显微镜显示，细丝具有高导电性且由金属银组成。瞬态和阻抗测量有效地区分了滞后模式。在金接触的器件中也发现了类似的响应，不过突然开关仅限于电极之间的纳米级间隙，这表明由于金的反应性较低，会形成更小、更不稳定的细丝。这些发现为推进基于钙钛矿的器件中的开关过程和理解滞后现象提供了有价值的见解。
