Enhancing Efficiencies of Polymer Photovoltaic Devices by Employing In-situ Electrochemical Doping in the Active Layer

Autor: Jia-Hsing Chen, 陳家欣
Rok vydání: 2011
Druh dokumentu: 學位論文 ; thesis
Popis: 99
In this study, we found that the formation of p–i–n junction through in situ electrochemical doping is a promising way to enhance the performance of polymer photovoltaic devices. We applied a pre-bias to metal triflate [LiCF3SO3, KCF3SO3, Ca(CF3SO3)2, Zn(CF3SO3)2] /poly (PEO)–incorporated poly (MEH-PPV)/(PCBM) photovoltaic devices to form p–i–n junctions in their active layers. Auger depth profile analyses and Alternating-current capacitance analyses of these doped devices revealed that the positive and negative ions distributed unequally to form an asymmetrical p-i-n structure in a thin layer of c.a. 100nm and the intrinsic layer became thinner when formed under a higher pre-bias voltage, respectively. Atomic force microscopy and transmission electron microscopy revealed that the addition of metal triflate/PEO to MEH-PPV/PCBM improved the morphology of the composite films. Among the various doped devices, the MEH-PPV/PCBM device incorporating a LiOTf/PEO mixture exhibited the highest power conversion efficiency, a 40% increase relative to that of the reference device (MEH-PPV/PCBM).
Databáze: Networked Digital Library of Theses & Dissertations