Title: Bridging donor-acceptor energy offset using organic dopants as energy ladders to improve open-circuit voltages in bulk-heterojunction solar cells
Authors: Chang, Jan-Kai
Kuo, Ya-Ching
Chen, Yu-Jen
Lo, An-Lun
Liu, I-Hsiu
Tseng, Wei-Hsuan
Wu, Kaung-Hsiung
Chen, Mei-Hsin
Wu, Chih-I
Department of Electrophysics
Keywords: Organic photovoltaics;Open-circuit voltage;Ternary cascade energy alignment
Issue Date: 1-Dec-2014
Abstract: A systematic way to improve the open circuit voltage of bulk-heterojunction (BHJ) organic photovoltaics is demonstrated by incorporating energy ladder material to form a ternary blend with cascade energy structures. We propose that doping organic molecules with appropriate energetic alignment to bridge the donor-acceptor energy offset can facilitate exciton dissociation and hence improve open-circuit voltage (V-oc) and power conversion efficiency. The cascade energy alignment structure is measured via ultraviolet photoemission spectroscopy. The Voc and power conversion efficiency of devices using the proposed schemes can be enhanced by 10% and 20%, respectively. The results provide a new path toward higher power conversion efficiency in BHJ systems by engineering the energy structures of the materials in the active layers. (C) 2014 Elsevier B.V. All rights reserved.
URI: http://dx.doi.org/10.1016/j.orgel.2014.08.052
ISSN: 1566-1199
DOI: 10.1016/j.orgel.2014.08.052
Volume: 15
Issue: 12
Begin Page: 3458
End Page: 3464
Appears in Collections:Articles

Files in This Item:

  1. 000345649200006.pdf