A high work function anode interfacial layer via mild temperature thermal decomposition of a C60F36 thin film on ITO

Abstract

A high work function anode interfacial layer has been developed via a mild temperature thermal decomposition of fluorinated fullerene (C 60 F 36 ) on ITO at 120 C. As revealed by in situ ultraviolet photoelectron spectroscopy (UPS) measurements, after the interfacial modification, the ITO electrode work function can be as high as $5.62 eV. It also possesses very good air stability even after the exposure to air for more than one day. The thermal annealing induced carbon-fluorine bond breaking was confirmed by in situ X-ray photoelectron spectroscopy (XPS) measurements. The residual F atoms are chemically bonded onto the ITO surface. Taking advantage of such a high work function anode interfacial layer on ITO, enhanced performance of a chloroaluminium phthalocyanine (ClAlPc)/fullerene (C 60 ) planar heterojunction based organic solar cell was observed. The performance enhancement is attributed to the higher anode WF together with the optimal nanoscale morphology, and hence better hole collection efficiency.

Manipulating the charge transfer at CuPc/graphene interface by O2plasma treatments

“…It is worth noting that the energy offset between the HOMO of CuPc and Fermi level of O 2 -G is $0.80 eV, whereas it increases to $1.10 eV for the growth of CuPc on pristine graphene. A smaller energy offset between the HOMO of CuPc and Fermi level of anode is benecial for reducing the possible energy loss during the hole extraction process, 47 and hence the enhanced device performance. In addition, it can be found that the IP of CuPc is different for CuPc on pristine graphene ($5.20 eV) and O 2 -G ($4.90 eV) substrate.…”

Effects of ITO Electrode Modification Using CsF Solution on Performance of Organic Light-Emitting Diodes

“…11a. 26 The Sn 3d peak located at a binding energy at 485.8 eV of base ITO and the Sn 3d peak of the UV-ozone treatment 10% CsF solution shift at 485.4 eV in Fig. 11b.…”

“…25,27 A few studies have reported that an ITO surface can be modified using C 60 F 36 to reduce the hole injection barrier and that CsF enhances the work function of the ITO electrode because of the existence of an ultrathin air-plasma-treated alkali fluoride layer. 26,27 The authors reported the hole-only devices using the ITO as the electrodes. They spin-coated CsF films with different concentration on top of ITO electrode and then baked the films.…”

Structure of C60F36: A Gas-Phase Electron Diffraction and Quantum Chemical Computational Study of a Remarkably Distorted Fluorofullerene

“…Because of the induced electronic polarization in the molecules surrounding the ionized molecules, the solid films of C 60 , C 60 F 36 , and C 60 F 48 demonstrate even higher EA values of 3.6, 5.2–5.6, and 5.2–5.4 eV, respectively. − High EAs, processability via gas and solution phases, as well as the thermal stability of fluorofullerenes enable their application as p-dopants for fabrication of inorganic and organic semiconductors, high-work function electrodes, and hole transport layers. Thin films of C 60 F 36 and C 60 F 48 were shown to capture electrons from the oxidized Si, H-terminated diamond, and indium tin oxide surfaces. C 60 F 36 and C 60 F 48 are effective low-volatile acceptors for p-doping organic semiconductors to increase their hole conductivity. , The organic p–i–n devices containing C 60 F 36 show efficiencies comparable to devices with the commonly used 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane …”

“…17−19 High EAs, processability via gas and solution phases, as well as the thermal stability of fluorofullerenes enable their application as p-dopants for fabrication of inorganic and organic semiconductors, highwork function electrodes, and hole transport layers. Thin films of C 60 F 36 and C 60 F 48 were shown to capture electrons from the oxidized Si, 18 H-terminated diamond, 20 and indium tin oxide 21 surfaces. C 60 F 36 and C 60 F 48 are effective low-volatile acceptors for p-doping organic semiconductors to increase their hole conductivity.…”