Stacking Orientation Mediation of Pentacene and Derivatives for High Open-Circuit Voltage Organic Solar Cells

Chi-Ta Chou; Chien-Hung Lin; Yian Tai; Chin-Hsin J Liu; Li-Chyong Chen; Kuei-Hsien Chen

doi:10.1021/jz201615v

Stacking Orientation Mediation of Pentacene and Derivatives for High Open-Circuit Voltage Organic Solar Cells

J Phys Chem Lett. 2012 May 3;3(9):1079-83. doi: 10.1021/jz201615v. Epub 2012 Apr 11.

Authors

Chi-Ta Chou¹, Chien-Hung Lin, Yian Tai¹, Chin-Hsin J Liu¹, Li-Chyong Chen, Kuei-Hsien Chen²

Affiliations

¹ †Department of Chemical Engineering, National Taiwan University of Science and Technology, Taipei 106, Taiwan.
² ⊥Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 106, Taiwan.

PMID: 26288039
DOI: 10.1021/jz201615v

Abstract

In this Letter, we investigated the effect of the molecular stacking orientation on the open circuit voltage (VOC) of pentacene-based organic solar cells. Two functionalized pentacenes, namely, 6,13-diphenyl-pentacene (DP-penta) and 6,13-dibiphenyl-4-yl-pentacene (DB-penta), were utilized. Different molecular stacking orientations of the pentacene derivatives from the pristine pentacene were identified by angle-dependent near-edge X-ray absorption fine structure measurements. It is concluded that pentacene molecules stand up on the substrate surface, while both functionalized pentacenes lie down. A significant increase of the VOC from 0.28 to 0.83 V can be achieved upon the utilization of functionalized pentacene, owing to the modulation of molecular stacking orientation, which induced a vacuum-level shift.

Keywords: VOC; molecular orientation; organic solar cell; photovoltaic.