Pininti Anil Reddy, Ball James M, Albaqami Munirah D, Petrozza Annamaria, Caironi Mario
Center for Nano Science and Technology @PoliMi, Istituto Italiano di Tecnologia, via G. Pascoli 70/3, Milano 20133, Italy.
Physics Department, Politecnico di Milano, Piazza L. da Vinci, 32, Milano 20133, Italy.
ACS Appl Energy Mater. 2021 Oct 25;4(10):10603-10609. doi: 10.1021/acsaem.1c01558. Epub 2021 Sep 29.
Charge transport in three-dimensional metal-halide perovskite semiconductors is due to a complex combination of ionic and electronic contributions, and its study is particularly relevant in light of their successful applications in photovoltaics as well as other opto- and microelectronic applications. Interestingly, the observation of field effect at room temperature in transistors based on solution-processed, polycrystalline, three-dimensional perovskite thin films has been elusive. In this work, we study the time-dependent electrical characteristics of field-effect transistors based on the model methylammonium lead iodide semiconductor and observe the drastic variations in output current, and therefore of apparent charge carrier mobility, as a function of the applied gate pulse duration. We infer this behavior to the accumulation of ions at the grain boundaries, which hamper the transport of carriers across the FET channel. This study reveals the dynamic nature of the field effect in solution-processed metal-halide perovskites and offers an investigation methodology useful to characterize charge carrier transport in such emerging semiconductors.
三维金属卤化物钙钛矿半导体中的电荷传输是离子和电子贡献的复杂组合，鉴于它们在光伏以及其他光电子和微电子应用中的成功应用，对其进行研究尤为重要。有趣的是，在基于溶液处理的多晶三维钙钛矿薄膜的晶体管中，室温下场效应的观测一直难以实现。在这项工作中，我们研究了基于典型的甲基碘化铅半导体的场效应晶体管的时间相关电学特性，并观察到输出电流以及表观电荷载流子迁移率随施加的栅极脉冲持续时间的函数发生剧烈变化。我们将这种行为归因于晶界处离子的积累，这阻碍了载流子在场效应晶体管沟道中的传输。这项研究揭示了溶液处理的金属卤化物钙钛矿中场效应的动态性质，并提供了一种用于表征此类新兴半导体中电荷载流子传输的研究方法。
