Photocurrent enhancements in a porphyrin-viologen linked compound under plasmonic and magnetic fields
Photocurrent enhancements in a porphyrin-viologen linked compound under plasmonic and magnetic fields
复制标题
DOI：
10.1142/s1088424615500133
复制
发表时间：
2015-04
影响因子：
1.5
通讯作者：
H. Yonemura;T. Niimi;S. Yamada
中科院分区：
文献类型：
--
作者：
H. Yonemura;T. Niimi;S. Yamada
采用静电逐层吸附和Langmuir-Blodgett法相结合的方法制备了含六个亚甲基的锌-卟啉-紫精(V2+)-纳米银(AgNP)复合膜。复合薄膜的入射光电流效率(IPCE)值高于不含V2+基团的ZnP(6)V薄膜，且远高于不含V2+的ZnP衍生膜。ZnP(6)V-AgNP复合薄膜的IPCE值的大幅增加可能是由于AgNPs的局域表面等离子体共振(LSPR)和连接到V2+部分时的光诱导分子内电子转移的共同作用。在外加磁场的情况下，ZnP(6)V-AgNP复合薄膜和ZnP(6)V薄膜的光电流增大。观察到了明显的磁场效应(MFE)，这两种薄膜均为ZnP(6)V-AgNP复合薄膜。在低磁场(B≤150-300mT)下，光电流随磁场增大而增大，在强磁场(B>；150-300mT)下，光电流不变。MFE可以用自由基对机制来解释。锌磷钒银纳米复合薄膜的磁能级大于锌磷钒薄膜的磁能级。与无磁场条件下的ZnP(6)V复合薄膜相比，在磁场作用下，AgNPs的LSPR效应使复合薄膜的光电流显著增加。
Zinc-porphyrin(ZnP)–viologen(V2+) linked compound containing six methylene group (ZnP(6)V)–silver nanoparticle (AgNP) composite films was fabricated by combining electrostatic layer-by-layer adsorption and the Langmuir–Blodgett method. The incident photo to photocurrent efficiency (IPCE) values of the ZnP(6)V–AgNP composite films are higher than those of the ZnP(6)V films and much higher than those of ZnP derivative films without V2+ moiety as a reference. The large increase in the IPCE values of the ZnP(6)V–AgNP composite films likely comes from a combination of localized surface plasmon resonance (LSPR) from AgNPs and photoinduced intramolecular electron-transfer upon linking to a V2+ moiety. The photocurrents of the ZnP(6)V–AgNP composite films and the ZnP(6)V films increase upon application of a magnetic field. Magnetic field effects (MFEs) were clearly observed for both ZnP(6)V–AgNP composite films and the ZnP(6)V films. Photocurrents increase with magnetic field under low magnetic fields (B ≤ 150–300 mT) and are constant under high magnetic fields (B > 150–300 mT). MFEs can be explained by a radical pair mechanism. The magnitude of the MFEs in the ZnP(6)V–AgNP composite films is higher than that in the ZnP(6)V films. A remarkable increase in photocurrent for the ZnP(6)V–AgNP composite films was observed because of LSPR from the AgNPs in the presence of a magnetic field when compared with the ZnP(6)V films in the absence of a magnetic field.