Solution-Processed Conducting Polymer/Metal Oxide Charge Generation Layer: Preparation, Electrical Properties, and Charge Generation Mechanism

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• 作者：Yong Lei ; Zhen Liu ; Chang-Jun Fan ; Xue-Feng Peng ; Xia-Xia Ji ; Guo-Qing Li ; Zu-Hong Xiong ; Xiao-Hui Yang
• 刊名：Journal of Physical Chemistry C
• 出版年：2017
• 出版时间：January 12, 2017
• 年：2017
• 卷：121
• 期：1
• 页码：793-800
• 全文大小：442K
• ISSN：1932-7455

文摘

Conducting polymer/metal oxide heterostructures have been commonly used in solution-processed tandem organic optoelectronic devices as charge generation layer (CGL) or charge recombination layer. However, the underlying working mechanism remains unexplored. We optimize the preparation of poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS)/zinc oxide (ZnO) CGL and report that the configurations and compositions of the interconnects significantly affect the performance of light-emitting devices. Two-unit and in particular the first reported three-unit solution-processed tandem polymer light-emitting devices show the luminance efficiency matching the total luminance efficiency of the constituent two and three light-emitting units, respectively. Current–voltage and capacitance–voltage measurements on the devices with various interconnects indicate that charges are generated at the PEDOT:PSS/ZnO interface. CGL-generated current can be described with the Richardson–Schottky thermal emission model, yielding the barrier height close to the “effective band gap” of the PEDOT:PSS/ZnO heterostructure.