A new research field of functional materials and device physics is rising that combines ionic transport with charge carrier modulation to realize emergent physical properties and discovery of metastable phases. The paradigm for enabling function extends far beyond carrier accumulation or depletion in band semiconductors or simply moving ions through an insulating electrolyte. Rather, by carefully selecting electronically or structurally fragile materials, one can collapse or open band gaps via extreme ionic dopant concentration, or reconfigure their entire crystal structure to create new phases. Electron–electron and electron–lattice interactions can be coupled or controlled independently in such systems via electric fields without thermal constraints by use of ionic dopants. The unifying theme across these studies is to introduce ions and electrons via electric fields through interfaces, with electrochemistry playing a dominant role. In this review, we briefly summarize this nascent field of iontronics and discuss principal results to date with examples from binary and complex oxides as well as selected 2D materials systems. We conclude the review by highlighting gaps in fundamental scientific understanding and prospects for the use of such novel devices in future electronic, photonic and energy technologies.

功能材料和器件物理的新研究领域正在兴起，它将离子传输与电荷载流子调制相结合，以实现新兴的物理特性和发现亚稳相。实现功能的范式远远超出了带状半导体中的载流子积累或耗尽，或仅使离子移动通过绝缘电解质。而是，通过仔细选择电子或结构上易碎的材料，可以通过极端的离子掺杂剂浓度破坏或打开带隙，或者重新配置其整个晶体结构以创建新的相。在这种系统中，通过使用离子掺杂剂，可以在没有热约束的情况下通过电场独立地耦合或控制电子-电子和电子-晶格相互作用。这些研究的统一主题是通过电场通过界面引入离子和电子，而电化学起主要作用。在本文中，我们简要概述了离子电子学的新兴领域，并以二元和复合氧化物以及选定的2D材料系统为例，讨论了迄今为止的主要结果。在总结本综述时，我们着重强调了在未来电子，光子和能源技术中使用此类新颖设备的基本科学理解和前景方面的差距。