Kim Gee Yeong, Senocrate Alessandro, Yang Tae-Youl, Gregori Giuliano, Grätzel Michael, Maier Joachim
Max Planck Institute for Solid State Research, Stuttgart, Germany.
Laboratory of Photonics and Interfaces, Ecole polytechnique Fédérale (EPFL) de Lausanne, Lausanne, Switzerland.
Nat Mater. 2018 May;17(5):445-449. doi: 10.1038/s41563-018-0038-0. Epub 2018 Mar 19.
In the same way as electron transport is crucial for information technology, ion transport is a key phenomenon in the context of energy research. To be able to tune ion conduction by light would open up opportunities for a wide realm of new applications, but it has been challenging to provide clear evidence for such an effect. Here we show through various techniques, such as transference-number measurements, permeation studies, stoichiometric variations, Hall effect experiments and the use of blocking electrodes, that light excitation enhances by several orders of magnitude the ionic conductivity of methylammonium lead iodide, the archetypal metal halide photovoltaic material. We provide a rationale for this unexpected phenomenon and show that it straightforwardly leads to a hitherto unconsidered photodecomposition path of the perovskite.
与电子传输对信息技术至关重要的方式相同，离子传输是能源研究背景下的一个关键现象。能够通过光来调节离子传导将为广泛的新应用开辟机会，但要为这种效应提供明确证据一直具有挑战性。在这里，我们通过各种技术，如迁移数测量、渗透研究、化学计量变化、霍尔效应实验以及使用阻挡电极，表明光激发将典型的金属卤化物光伏材料甲基碘化铅的离子电导率提高了几个数量级。我们为这一意外现象提供了一个原理，并表明它直接导致了一种迄今未被考虑的钙钛矿光分解路径。
