Department of Materials Science and Engineering, University of Tennessee , Knoxville, Tennessee 37996, United States.
Center for Nanophase Materials Sciences, Oak Ridge National Laboratory , Oak Ridge, Tennessee 37831, United States.
J Am Chem Soc. 2017 Dec 6;139(48):17285-17288. doi: 10.1021/jacs.7b10416. Epub 2017 Nov 21.
Hybrid perovskites, as emerging multifunctional semiconductors, have demonstrated dual electronic/ionic conduction properties. We report a metal/ion interaction induced p-i-n junction across slightly n-type doped MAPbI single crystals with Au/MAPbI/Ag configuration based on interface dependent Seebeck effect, Hall effect and time-of-flight secondary ion mass spectrometry analysis. The organic cations (MA) interact with Au atoms, forming positively charged coordination complexes at Au/MAPbI interface, whereas iodine anions (I) can react with Ag contacts, leading to interfacial ionic polarization. Such metal/ion interactions establish a p-doped region near the Au/MAPbI interface due to the formation of MA vacancies, and an n-doped region near the Ag/MAPbI interface due to formation of I vacancies, consequently forming a p-i-n junction across the crystal in Au/MAPbI/Ag configuration. Therefore, the metal/ion interaction plays a role in determining the surface electronic structure and semiconducting properties of hybrid perovskites.
钙钛矿作为新兴的多功能半导体，表现出了电子/离子双传导特性。我们通过基于界面依赖的塞贝克效应、霍尔效应和飞行时间二次离子质谱分析，报告了一种在略微 n 型掺杂的 MAPbI 单晶体上，通过金属/离子相互作用诱导的 p-i-n 结，结构为 Au/MAPbI/Ag。有机阳离子（MA）与 Au 原子相互作用，在 Au/MAPbI 界面形成带正电荷的配位复合物，而碘阴离子（I）可以与 Ag 接触反应，导致界面离子极化。这种金属/离子相互作用在 Au/MAPbI 界面附近形成了 p 掺杂区，因为 MA 空位的形成，在 Ag/MAPbI 界面附近形成了 n 掺杂区，因为 I 空位的形成，因此在 Au/MAPbI/Ag 结构中形成了贯穿整个晶体的 p-i-n 结。因此，金属/离子相互作用在决定钙钛矿的表面电子结构和半导体性质方面起着重要作用。
