Comparison of short and long wavelength absorption electron donor materials in C-60-based planar heterojunction organic photovoltaics
Journal
Organic Electronics
Journal Volume
13
Journal Issue
10
Pages
2118-2129
Date Issued
2012
Author(s)
Abstract
Buckminsterfullerene, C60-based planar heterojunction (PHJ) organic photovoltaics (OPVs) have been created using a short wavelength absorption (λmax = 490 nm) electron-donating bis(naphthylphenylaminophenyl)fumaronitrile (NPAFN). NPAFN exhibits a hole mobility greater than 0.07 cm2 V-1 s-1 as determined by its field-effect transistor. It can be attributed to such hole mobility that enables a thin layer (<10 nm) NPAFN in PHJ OPV, ITO/NPAFN/C60/bathocuproine/Al. Because of the low lying HOMO energy level (5.75 eV) of NPAFN and relatively high ionization potential ITO (∼5.58 eV), such OPVs exhibit a very high open circuit voltage of ∼1.0 V, relatively high fill factor of 0.60, and a relatively high shunt resistance of 1100 Ω cm-2, which all compensate for a relatively low short circuit current of 3.15 mA cm-2 due to the short absorption wavelength and inferred short exciton diffusion length of NPAFN. Altogether, NPAFN OPVs display a power conversion efficiency (ηPC) of 2.22%, which is better than other long wavelength absorption materials in similar PHJ OPVs, such as pentacene (λmax 670 nm, HOMO 5.12 eV, ηPC 1.50%) and copper phthalocyanine (λmax 624, 695 nm, HOMO 5.17 eV, ηPC 1.43%). © 2012 Elsevier B.V. All rights reserved.
Subjects
Field-effect transistor; Fill factor; Open circuit voltage; Planar heterojunction organic photovoltaics
SDGs
Other Subjects
Heterojunctions; Hole mobility; Ionization potential; Open circuit voltage; Photovoltaic effects; Absorption wavelengths; Buckminsterfullerenes; Copper phthalocyanine; Exciton diffusion length; Fill factor; Long-wavelength absorption; Organic photovoltaics; Power conversion efficiencies; Field effect transistors
Type
journal article