Improvement in Half-Life of Organic Solar Cells by Using a Blended Hole Extraction Layer Consisting of PEDOT:PSS and Conjugated Polymer Electrolyte

Eui Jin Lee; Jae Pil Han; Seung Eun Jung; Min Hee Choi; Doo Kyung Moon

doi:10.1021/acsami.6b09846

Improvement in Half-Life of Organic Solar Cells by Using a Blended Hole Extraction Layer Consisting of PEDOT:PSS and Conjugated Polymer Electrolyte

ACS Appl Mater Interfaces. 2016 Nov 23;8(46):31791-31798. doi: 10.1021/acsami.6b09846. Epub 2016 Nov 11.

Authors

Eui Jin Lee¹, Jae Pil Han¹, Seung Eun Jung¹, Min Hee Choi¹, Doo Kyung Moon¹

Affiliation

¹ Department of Materials Chemistry and Engineering, Konkuk University , 120, Neungdong-ro, Gwangjin-gu, Seoul 05029, Korea.

PMID: 27766850
DOI: 10.1021/acsami.6b09846

Abstract

In this study, we fabricated conventional structured organic solar cells (OSCs) by introducing a hole extraction layer (HEL) that consisted of poly(3,4-ethylenedioxythiophene):polystyrenesulfonate (PEDOT:PSS) and conjugated polymer electrolyte (CPE) poly[9,9-bis(4'-sulfonatobutyl)fluorene-alt-thiophene] (PFT-D). PFT-D has a -SO₃^- functional group that acts as a conjugate base against the -SO₃H of PSS. In addition, the molecular dipole of PFT-D can screen the Coulombic attraction between PEDOT chains and PSS chains. By blending PEDOT:PSS and PFT-D, the acidity of the HEL solution and changes to the surface morphology and potential of the HEL film as a function of exposure time in air were reduced. As a result, the half-life of the OSC fabricated with blended HEL was five times better at room temperature and 40% humidity without encapsulation as compared to the pristine PEDOT:PSS-based device.

Keywords: conjugated polymer electrolytes; hole extraction layer; morphological stability; organic solar cell; phase separation; stability; surface potential.