Comparison of short and long wavelength absorption electron donor materials in C-60-based planar heterojunction organic photovoltaics

Liu, S. W.S. W.LiuSu, W. C.W. C.SuLee, C. C.C. C.LeeLin, C. F.C. F.LinYeh, S. C.S. C.YehChen, C. T.C. T.ChenLee, J. H.J. H.LeeJIUN-HAW LEE2018-09-102018-09-102012http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000309591200046&KeyUID=WOS:000309591200046http://scholars.lib.ntu.edu.tw/handle/123456789/372437Buckminsterfullerene, 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.Field-effect transistor; Fill factor; Open circuit voltage; Planar heterojunction organic photovoltaics[SDGs]SDG7Heterojunctions; 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 transistorsComparison of short and long wavelength absorption electron donor materials in C-60-based planar heterojunction organic photovoltaicsjournal article10.1016/j.orgel.2012.06.006