Le Corre Vincent M, Duijnstee Elisabeth A, El Tambouli Omar, Ball James M, Snaith Henry J, Lim Jongchul, Koster L Jan Anton
Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands.
Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU, United Kingdom.
ACS Energy Lett. 2021 Mar 12;6(3):1087-1094. doi: 10.1021/acsenergylett.0c02599. Epub 2021 Feb 26.
Space-charge-limited current (SCLC) measurements have been widely used to study the charge carrier mobility and trap density in semiconductors. However, their applicability to metal halide perovskites is not straightforward, due to the mixed ionic and electronic nature of these materials. Here, we discuss the pitfalls of SCLC for perovskite semiconductors, and especially the effect of mobile ions. We show, using drift-diffusion (DD) simulations, that the ions strongly affect the measurement and that the usual analysis and interpretation of SCLC need to be refined. We highlight that the trap density and mobility cannot be directly quantified using classical methods. We discuss the advantages of pulsed SCLC for obtaining reliable data with minimal influence of the ionic motion. We then show that fitting the pulsed SCLC with DD modeling is a reliable method for extracting mobility, trap, and ion densities simultaneously. As a proof of concept, we obtain a trap density of 1.3 × 10 cm, an ion density of 1.1 × 10 cm, and a mobility of 13 cm V s for a MAPbBr single crystal.
空间电荷限制电流（SCLC）测量已被广泛用于研究半导体中的电荷载流子迁移率和陷阱密度。然而，由于金属卤化物钙钛矿材料具有离子和电子混合的性质，SCLC测量在这些材料上的应用并非简单直接。在此，我们讨论SCLC用于钙钛矿半导体时存在的问题，特别是可移动离子的影响。我们通过漂移扩散（DD）模拟表明，离子对测量有强烈影响，并且SCLC通常的分析和解释需要改进。我们强调，不能使用经典方法直接量化陷阱密度和迁移率。我们讨论了脉冲SCLC在获取受离子运动影响最小的可靠数据方面的优势。然后我们表明，用DD模型拟合脉冲SCLC是一种同时提取迁移率、陷阱和离子密度的可靠方法。作为概念验证，我们得到了MAPbBr单晶的陷阱密度为1.3×10 cm、离子密度为1.1×10 cm以及迁移率为13 cm² V⁻¹ s⁻¹。 （注：原文中部分数据单位不完整，翻译时保留原文形式）
