College of Electronic Information and Optical Engineering, Nankai University , Tianjin 300071, China.
ACS Appl Mater Interfaces. 2016 May 25;8(20):12836-42. doi: 10.1021/acsami.6b02706. Epub 2016 May 12.
In this work, a facile and low temperature processed anodic oxidation approach is proposed for fabricating compact and homogeneous titanium dioxide film (AO-TiO2). In order to realize morphology and thickness control of AO-TiO2, the theory concerning anodic oxidation (AO) is unveiled and the influence of relevant parameters during the process of AO such as electrolyte ingredient and oxidation voltage on AO-TiO2 formation is observed as well. Meanwhile, we demonstrate that the planar perovskite solar cells (p-PSCs) fabricated in ambient air and utilizing optimized AO-TiO2 as electron transport layer (ETL) can deliver repeatable power conversion efficiency (PCE) over 13%, which possess superior open-circuit voltage (Voc) and higher fill factor (FF) compared to its counterpart utilizing conventional high temperature processed compact TiO2 (c-TiO2) as ETL. Through a further comparative study, it is indicated that the improvement of device performance should be attributed to more effective electron collection from perovskite layer to AO-TiO2 and the decrease of device series resistance. Furthermore, hysteresis effect about current density-voltage (J-V) curves in TiO2-based p-PSCs is also unveiled.
在这项工作中，提出了一种简便且低温处理的阳极氧化方法，用于制备致密且均匀的二氧化钛薄膜（AO-TiO2）。为了实现 AO-TiO2 的形态和厚度控制，揭示了有关阳极氧化（AO）的理论，并观察了电解质成分和氧化电压等相关参数对 AO-TiO2 形成的影响。同时，我们证明了在环境空气中制造的平面钙钛矿太阳能电池（p-PSCs），并利用优化的 AO-TiO2 作为电子传输层（ETL），可以提供超过 13%的可重复功率转换效率（PCE），与利用传统高温处理致密 TiO2（c-TiO2）作为 ETL 的同类产品相比，具有更高的开路电压（Voc）和更高的填充因子（FF）。通过进一步的比较研究，表明器件性能的提高归因于从钙钛矿层到 AO-TiO2 的更有效的电子收集，以及器件串联电阻的降低。此外，还揭示了基于 TiO2 的 p-PSCs 中电流密度-电压（J-V）曲线的滞后效应。
