title: Graphene supported platinum nanoparticle counter-electrode for enhanced performance of dye-sensitized solar cells.
abstract: Composites of few layered graphene (G) and platinum (Pt) nanoparticles (NP) with different loadings of Pt were used as counter electrode (CE) in dye-sensitized solar cell (DSSC). NPs were deposited directly on to G using pulsed laser ablation method (PLD). DSSCs formed using the composite CEs show improved performance compared to conventional Pt thin film electrode (Std Pt) and unsupported Pt NPs. Composite with 27% loading of Pt shows 45% higher efficiency (η = 2.9%), greater short circuit current (J(sc) = 6.67 mA cm(-2)), and open circuit voltage (V(oc) = 0.74 V) without any loss of the fill factor (FF = 58%) as compared to the cells fabricated using Std Pt electrodes. Values of η, J(sc) and V(oc) for DSSC using Std Pt CE were 2%, 5.05 mA cm(-2) and 0.68 V, respectively. Electrochemical impedance spectroscopy using I(-)(3)/I(-) redox couple confirm lower values of charge transfer resistance for the composite electrodes, e.g., 2.36 Ω cm(2) as opposed to 7.73 Ω cm(2) of Std Pt. The better catalytic activity of these composite materials is also reflected in the stronger I(-)(3) reduction peaks in cyclic voltammetry scans.
authors.affiliation: Department of Physics, Indian Institute of Technology Bombay, Mumbai 400 076, India.
authors.forename: Reeti
authors.initials: R
authors.lastname: Bajpai
authors.forename: Soumyendu
authors.initials: S
authors.lastname: Roy
authors.forename: Pragyensh
authors.initials: P
authors.lastname: Kumar
authors.forename: Preeti
authors.initials: P
authors.lastname: Bajpai
authors.forename: Neha
authors.initials: N
authors.lastname: Kulshrestha
authors.forename: Javad
authors.initials: J
authors.lastname: Rafiee
authors.forename: Nikhil
authors.initials: N
authors.lastname: Koratkar
authors.forename: D S
authors.initials: DS
authors.lastname: Misra