WCU Hybrid Materials Program, Department of Materials Science and Engineering, Research Institute of Advanced Materials, Seoul National University , Seoul 08226, Korea.
Department of Materials Science and Engineering and Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign , Urbana, Illinois 61801, United States.
ACS Appl Mater Interfaces. 2017 Sep 20;9(37):31931-31939. doi: 10.1021/acsami.7b09745. Epub 2017 Sep 5.
One-dimensionally elongated nanoparticles with type-II staggered band offset are of potential use as light-harvesting materials for photovoltaics, but only a limited attention has been given to elucidate the factors governing the cell performance obtainable from such materials. Herein, we describe a combined strategy to enhance charge collection from CdSe/CdSeTe type-II heterojunction nanorods (HNRs) utilized as light harvesters for sensitized solar cells. By integrating morphology- and composition-tuned type-II HNRs into solar cells, factors that yield interfaces favorable both for the electron injection into TiO and hole transfer to electrolyte are examined. Furthermore, it is shown that a more efficient photovoltaic system results from cosensitization with CdS quantum dots (QDs) predeposited on a TiO scaffold, which improves charge collection from HNRs. Electrochemical impedance spectroscopy (EIS) analysis suggests that such a synergistically enhanced system benefits from the decreased recombination within HNRs and facilitated charge transport through the cosensitized TiO electrode, even with the activation of a recombination path presumably related to the photogenerated holes in CdS QDs.
具有 II 型交错能带偏移的一维拉长纳米粒子可用作光收集材料用于光伏，但只有有限的注意力被用于阐明从这种材料获得的电池性能的因素。在此，我们描述了一种联合策略，以增强作为敏化太阳能电池光收集器的 CdSe/CdSeTe 型 II 异质结纳米棒 (HNR) 的电荷收集。通过将形态和组成可调的 II 型 HNR 集成到太阳能电池中，研究了产生有利于电子注入 TiO 和空穴转移到电解质的界面的因素。此外，结果表明，通过预先沉积在 TiO 支架上的 CdS 量子点 (QD) 共敏化，可以获得更有效的光伏系统，从而提高了 HNR 的电荷收集效率。电化学阻抗谱 (EIS) 分析表明，即使通过与 CdS QD 中的光生空穴有关的复合路径的激活，这种协同增强的系统也受益于 HNR 内复合的减少和通过共敏化 TiO 电极的电荷传输的促进。
