TY - JOUR
T1 - Roughening conjugated polymer surface for enhancing the charge collection efficiency of sequentially deposited polymer/fullerene photovoltaics
AU - Jang, Yoonhee
AU - Seo, Ji Won
AU - Seok, Jeesoo
AU - Lee, Jung Yong
AU - Kim, Kyungkon
N1 - Publisher Copyright:
© 2015 by the authors; licensee MDPI, Basel, Switzerland.
PY - 2015
Y1 - 2015
N2 - A method that enables the formation of a rough nano-scale surface for conjugated polymers is developed through the utilization of a polymer chain ordering agent (OA). 1-Chloronaphthalene (1-CN) is used as the OA for the poly(3-hexylthiophene-2,5-diyl) (P3HT) layer. The addition of 1-CN to the P3HT solution improves the chain ordering of the P3HT during the film formation process and increases the surface roughness of the P3HT film compared to the film prepared without 1-CN. The roughened surface of the P3HT film is utilized to construct a P3HT/fullerene bilayer organic photovoltaic (OPV) by sequential solution deposition (SqSD) without thermal annealing process. The power conversion efficiency (PCE) of the SqSD-processed OPV utilizing roughened P3HT layer is 25% higher than that utilizing a plain P3HT layer. It is revealed that the roughened surface of the P3HT increases the heterojunction area at the P3HT/fullerene interface and this resulted in improved internal charge collection efficiency, as well as light absorption efficiency. This method proposes a novel way to improve the PCE of the SqSD-processed OPV, which can be applied for OPV utilizing low band gap polymers. In addition, this method allows for the reassessment of polymers, which have shown insufficient performance in the BSD process.
AB - A method that enables the formation of a rough nano-scale surface for conjugated polymers is developed through the utilization of a polymer chain ordering agent (OA). 1-Chloronaphthalene (1-CN) is used as the OA for the poly(3-hexylthiophene-2,5-diyl) (P3HT) layer. The addition of 1-CN to the P3HT solution improves the chain ordering of the P3HT during the film formation process and increases the surface roughness of the P3HT film compared to the film prepared without 1-CN. The roughened surface of the P3HT film is utilized to construct a P3HT/fullerene bilayer organic photovoltaic (OPV) by sequential solution deposition (SqSD) without thermal annealing process. The power conversion efficiency (PCE) of the SqSD-processed OPV utilizing roughened P3HT layer is 25% higher than that utilizing a plain P3HT layer. It is revealed that the roughened surface of the P3HT increases the heterojunction area at the P3HT/fullerene interface and this resulted in improved internal charge collection efficiency, as well as light absorption efficiency. This method proposes a novel way to improve the PCE of the SqSD-processed OPV, which can be applied for OPV utilizing low band gap polymers. In addition, this method allows for the reassessment of polymers, which have shown insufficient performance in the BSD process.
KW - Bilayer organic photovoltaics
KW - Ordering agent
KW - Organic photovoltaics
KW - Sequential deposition
UR - http://www.scopus.com/inward/record.url?scp=84940544174&partnerID=8YFLogxK
U2 - 10.3390/polym7081466
DO - 10.3390/polym7081466
M3 - Article
AN - SCOPUS:84940544174
SN - 2073-4360
VL - 7
SP - 1497
EP - 1509
JO - Polymers
JF - Polymers
IS - 8
ER -