Here in this paper, we demonstrate a facile technique for creating the mixed formamidinium（HN = CHNH_3~＋, FA~＋）and methylammonium（CH_3NH_3~＋, MA~＋） cations in the lead iodide perovskite. This technique entails...Here in this paper, we demonstrate a facile technique for creating the mixed formamidinium（HN = CHNH_3~＋, FA~＋）and methylammonium（CH_3NH_3~＋, MA~＋） cations in the lead iodide perovskite. This technique entails a facile drop-casting of formamidinium iodide（FAI） solutions on as-prepared MAPbI_3 perovskite thin films under the controlled conditions,which leads to controllable displacement of the MA~＋ cations by FA~＋ cations in the perovskite structure at room temperature. Uniform and controllable mixed organic cation perovskite thin films without a ＂bi-layered＂ or graded structure are achieved. By applying this approach to photovoltaic devices, we are able to improve the performances of devices through extending their optical-absorption onset further into the infrared region to enhance solar-light harvesting. Additionally,this work provides a simple and efficient technique to tune the structural, electrical, and optoelectronic properties of the light-harvesting materials for high-performance perovskite solar cells.展开更多
基金Project supported by the Fundamental Research Funds for the Central Universities,China(Grant No.2015QNA09)
文摘Here in this paper, we demonstrate a facile technique for creating the mixed formamidinium（HN = CHNH_3~＋, FA~＋）and methylammonium（CH_3NH_3~＋, MA~＋） cations in the lead iodide perovskite. This technique entails a facile drop-casting of formamidinium iodide（FAI） solutions on as-prepared MAPbI_3 perovskite thin films under the controlled conditions,which leads to controllable displacement of the MA~＋ cations by FA~＋ cations in the perovskite structure at room temperature. Uniform and controllable mixed organic cation perovskite thin films without a ＂bi-layered＂ or graded structure are achieved. By applying this approach to photovoltaic devices, we are able to improve the performances of devices through extending their optical-absorption onset further into the infrared region to enhance solar-light harvesting. Additionally,this work provides a simple and efficient technique to tune the structural, electrical, and optoelectronic properties of the light-harvesting materials for high-performance perovskite solar cells.
