Thakur Ujwal K, Kisslinger Ryan, Shankar Karthik
Department of Electrical and Computer Engineering, University of Alberta, Edmonton, AB T6G 1H9, Canada.
National Research Council, National Institute for Nanotechnology, 11421 Saskatchewan Drive NW, Edmonton, AB T6G 2M9, Canada.
Nanomaterials (Basel). 2017 Apr 29;7(5):95. doi: 10.3390/nano7050095.
The electron diffusion length () is smaller than the hole diffusion length () in many halide perovskite semiconductors meaning that the use of ordered one-dimensional (1D) structures such as nanowires (NWs) and nanotubes (NTs) as electron transport layers (ETLs) is a promising method of achieving high performance halide perovskite solar cells (HPSCs). ETLs consisting of oriented and aligned NWs and NTs offer the potential not merely for improved directional charge transport but also for the enhanced absorption of incoming light and thermodynamically efficient management of photogenerated carrier populations. The ordered architecture of NW/NT arrays affords superior infiltration of a deposited material making them ideal for use in HPSCs. Photoconversion efficiencies (PCEs) as high as 18% have been demonstrated for HPSCs using 1D ETLs. Despite the advantages of 1D ETLs, there are still challenges that need to be overcome to achieve even higher PCEs, such as better methods to eliminate or passivate surface traps, improved understanding of the hetero-interface and optimization of the morphology (i.e., length, diameter, and spacing of NWs/NTs). This review introduces the general considerations of ETLs for HPSCs, deposition techniques used, and the current research and challenges in the field of 1D ETLs for perovskite solar cells.
在许多卤化物钙钛矿半导体中，电子扩散长度（）小于空穴扩散长度（），这意味着使用诸如纳米线（NWs）和纳米管（NTs）等有序一维（1D）结构作为电子传输层（ETLs）是实现高性能卤化物钙钛矿太阳能电池（HPSCs）的一种有前景的方法。由定向排列的NWs和NTs组成的ETLs不仅具有改善定向电荷传输的潜力，还具有增强对入射光的吸收以及对光生载流子群体进行热力学高效管理的潜力。NW/NT阵列的有序结构使得沉积材料具有优异的浸润性，使其成为用于HPSCs的理想选择。使用1D ETLs的HPSCs已证明其光电转换效率（PCEs）高达18%。尽管1D ETLs具有诸多优势，但要实现更高的PCEs仍有一些挑战需要克服，例如消除或钝化表面陷阱的更好方法、对异质界面的更深入理解以及形态优化（即NWs/NTs的长度、直径和间距）。本综述介绍了用于HPSCs的ETLs的一般考虑因素、所使用的沉积技术以及钙钛矿太阳能电池1D ETLs领域的当前研究和挑战。
