Kang Han Byul, Chang Jiyoung, Koh Kisik, Lin Liwei, Cho Yong Soo
Department of Materials Science and Engineering, Yonsei University , Seoul 120-749, Korea.
ACS Appl Mater Interfaces. 2014 Jul 9;6(13):10576-82. doi: 10.1021/am502234q. Epub 2014 Jun 25.
Enhanced piezoelectric and energy-harvesting characteristics of Mn-doped (Na0.5K0.5)NbO3 (NKN) nanofibers have been investigated with actual fabrication of potential flexible nanogenerators. The electrospinning process of nanofibers has been initially optimized with the proper level of chelating agent and annealing temperature. High quality nanofibers are successfully obtained only by means of a certain level of doped-Mn, which incorporates into the NKN perovskite structure and facilitates significant grain growth. A single-particle-stacked structure along the direction of fiber length becomes more evident with increasing Mn content. An XPS analysis confirms that Mn exists in multivalent states of Mn(2+)/Mn(3+). The effective piezoelectric coefficient of the nanofibers is found to be enhanced by 5 times with Mn-doping up to 3 mol % as characterized by piezoelectric force microscopy. The resultant flexible nanogenerators on PES films have exhibited ∼0.3 V output voltage and ∼50 nA output current under a bending strain.
通过实际制备潜在的柔性纳米发电机，研究了锰掺杂（Na0.5K0.5）NbO3（NKN）纳米纤维增强的压电和能量收集特性。首先通过适当水平的螯合剂和退火温度对纳米纤维的电纺丝工艺进行了优化。仅通过一定水平的掺杂锰才能成功获得高质量的纳米纤维，锰掺入NKN钙钛矿结构并促进显著的晶粒生长。随着锰含量的增加，沿纤维长度方向的单粒子堆叠结构变得更加明显。XPS分析证实锰以Mn(2+)/Mn(3+)的多价态存在。通过压电力显微镜表征，发现锰掺杂量高达3 mol%时，纳米纤维的有效压电系数提高了5倍。在PES薄膜上制备的柔性纳米发电机在弯曲应变下表现出约0.3 V的输出电压和约50 nA的输出电流。
