文献类型：期刊文献

英文题名：New pyrido[3,4-b] pyrazine-based sensitizers for efficient and stable dye-sensitized solar cells

作者：Ying, Weijiang[1,2];Yang, Jiabao[1,2,3,4];Wielopolski, Mateusz[5];Moehl, Thomas[3,4];Moser, Jacques-E.[5];Comte, Pascal[3,4];Hua, Jianli[1,2];Zakeeruddin, Shaik M.[3,4];Tian, He[1,2];Graetzel, Michael[3,4]

机构：[1]E China Univ Sci & Technol, Key Lab Adv Mat, Shanghai 200237, Peoples R China;[2]E China Univ Sci & Technol, Inst Fine Chem, Shanghai 200237, Peoples R China;[3]Ecole Polytech Fed Lausanne, Lab Photon & Interfaces, CH-1015 Lausanne, Switzerland;[4]Ecole Polytech Fed Lausanne, Inst Chem Sci & Engn, CH-1015 Lausanne, Switzerland;[5]Ecole Polytech Fed Lausanne, Inst Chem Sci & Engn, Photochem Dynam Grp, CH-1015 Lausanne, Switzerland

年份：2014

卷号：5

期号：1

起止页码：206

外文期刊名：CHEMICAL SCIENCE

收录：;WOS:【SCI-EXPANDED(收录号:WOS:000327601600025)】；

基金：This work was supported by NSFC/China (2116110444, 21172073 and 91233207), the National Basic Research 973 Program (2013CB733700), and the Fundamental Research Funds for the Central Universities (WJ0913001). MG would like to thank the Swiss National Science Foundation and ECR advanced Grant Agreement no. 247404 under the CE-Mesolight project funded by the European community's 7th FWP for the financial support. J.-E. M. thanks NCCR MUST, a research instrument of the Swiss National Science Foundation for generous support. Yang would like to thank the funding of the visiting program which is supported by China Scholarship Council (CSC). We thank Dr Carole Gratzel at the EPFL for fruitful discussion.

语种：英文

摘要：A series of new pyrido[3,4-b] pyrazine-based organic sensitizers (PP-I and APP-I-IV) containing different donors and p-spacers have been synthesized and employed in dye-sensitized solar cells (DSSCs). The absorption spectra properties of dyes are analysed by density functional theory (DFT). The calculated results in combination with the experiments suggest that the absorption characteristics and excited state features will mainly be dominated by charge transfer transitions from the highest occupied molecular orbital (HOMO) to the lowest unoccupied molecular orbital (LUMO) and to higher LUMO orbitals. Furthermore, attaching the octyloxy groups significantly extends the p-conjugation of the donor in APPIV, which raises the HOMO energy and facilitates its oxidation. As a consequence, APP-IV exhibits the lowest HOMO-LUMO energy gap among all dyes, which, in turn, corresponds well with the red shift of the absorption spectra. Transient photovoltage and photocurrent decay experiments as well as electrochemical impedance spectroscopy indicate that the electron lifetime and charge recombination resistance are increased due to the introduction of octyloxy chains on the donor unit, resulting in the high photovoltage based on APP-IV. It was found that APP-IV based DSSCs with liquid electrolyte display the highest power conversion efficiency (PCE) of 7.12%. Importantly, a PCE of 6.20% has been achieved for APP-IV based DSSCs with ionic-liquid electrolytes and retained 97% of the initial value after continuous light soaking for 1000 h at 60 degrees C. This renders these pyrido[3,4-b] pyrazine-based sensitizers quite promising candidates for highly efficient and stable DSSCs.