Correlation between energy level alignment and device performance in planar heterojunction organic photovoltaics

被引:25
作者
Akaike, Kouki [1 ]
Kubozono, Yoshihiro [1 ]
机构
[1] Okayama Univ, Surface Sci Res Lab, Okayama 7008530, Japan
关键词
Energy level alignment; Organic photovoltaics; Donor/acceptor interface; Kelvin probe method; Interfacial electronic structure; CHARGE-TRANSFER; INTERFACES; BATHOCUPROINE; EFFICIENCY; ACCEPTOR; DIPOLE; DONOR; METAL;
D O I
10.1016/j.orgel.2012.09.025
中图分类号
T [工业技术];
学科分类号
08 ;
摘要
Information on the interfacial electronic structure in organic photovoltaics (OPVs) is essential for fully understanding features of device operation such as the photocurrent generation and relative energy band offsets at the donor/acceptor interface, which directly affect the open circuit voltage (V-oc). Kelvin probe (KP) measurements fully reveal the energy level alignment in a prototype OPV with a copper phthalocyanine (CuPc)/fullerene (C-60) planar heterojunction. Energy level pinning at the CuPc/C-60 junction fixes the energy band offsets of C-60. A downward energy shift of about 0.9 eV appears at the C-60/bathocuproine junction, which may act as a hole-blocking barrier. A combination of KP and current density-voltage measurements indicates that photocurrent generation depends strongly on the magnitude of the upward energy shift at the CuPc/C-60 junction. The dependence of V-oc on the substrate work function is also discussed in terms of the energy level alignment at indium tin oxide/CuPc/C-60 junctions. (c) 2012 Elsevier B.V. All rights reserved.
引用
收藏
页码:1 / 7
页数:7
相关论文
共 39 条
[1]  
Akaike K., UNPUBLISHED RESULT
[2]   Impact of Ground-State Charge Transfer and Polarization Energy Change on Energy Band Offsets at Donor/Acceptor Interface in Organic Photovoltaics [J].
Akaike, Kouki ;
Kanai, Kaname ;
Ouchi, Yukio ;
Seki, Kazuhiko .
ADVANCED FUNCTIONAL MATERIALS, 2010, 20 (05) :715-721
[3]   Energy-Level Alignment at Organic/Metal and Organic/Organic Interfaces [J].
Braun, Slawomir ;
Salaneck, William R. ;
Fahlman, Mats .
ADVANCED MATERIALS, 2009, 21 (14-15) :1450-1472
[4]   Influence of the electrode work function on the energy level alignment at organic-organic interfaces [J].
Braun, Slawomir ;
de Jong, Michel P. ;
Osikowicz, Wojciech ;
Salaneck, William R. .
APPLIED PHYSICS LETTERS, 2007, 91 (20)
[5]   Molecular Understanding of Organic Solar Cells: The Challenges [J].
Bredas, Jean-Luc ;
Norton, Joseph E. ;
Cornil, Jerome ;
Coropceanu, Veaceslav .
ACCOUNTS OF CHEMICAL RESEARCH, 2009, 42 (11) :1691-1699
[6]   Interface investigation and engineering - achieving high performance polymer photovoltaic devices [J].
Chen, Li-Min ;
Xu, Zheng ;
Hong, Ziruo ;
Yang, Yang .
JOURNAL OF MATERIALS CHEMISTRY, 2010, 20 (13) :2575-2598
[7]   Investigation of the interface formation between calcium and tris-(8-hydroxy quinoline) aluminum [J].
Choong, VE ;
Mason, MG ;
Tang, CW ;
Gao, YG .
APPLIED PHYSICS LETTERS, 1998, 72 (21) :2689-2691
[8]   Enhanced performance of a CuPc: PCBM based solar cell using bathocuproine BCP or nanostructured TiO2 as hole-blocking layer [J].
Derouiche, Hassen ;
Ben Miled, Hatem ;
Mohamed, Abdelatif Belhadj .
PHYSICA STATUS SOLIDI A-APPLICATIONS AND MATERIALS SCIENCE, 2010, 207 (02) :479-483
[9]   Influence of indium tin oxide treatment using UV-ozone and argon plasma on the photovoltaic parameters of devices based on organic discotic materials [J].
Destruel, P ;
Bock, H ;
Séguy, I ;
Jolinat, P ;
Oukachmih, M ;
Bedel-Pereira, E .
POLYMER INTERNATIONAL, 2006, 55 (06) :601-607
[10]   On the Role of Bathocuproine in Organic Photovoltaic Cells [J].
Gommans, Hans ;
Verreet, Bregt ;
Rand, Barry P. ;
Muller, Robert ;
Poortmans, Jef ;
Heremans, Paul ;
Genoe, Jan .
ADVANCED FUNCTIONAL MATERIALS, 2008, 18 (22) :3686-3691