Azimah Omar, Muhamad Saipul Fakir, Khairus Syifa Hamdan, Nurul Hidayah Rased and Nasrudin Abd. Rahim
The purpose of this paper is to investigate the chemical, optical and photovoltaic properties of titanium dioxide/reduced graphene oxide (TiO2/rGO) photoanodes immersed in natural…
Abstract
Purpose
The purpose of this paper is to investigate the chemical, optical and photovoltaic properties of titanium dioxide/reduced graphene oxide (TiO2/rGO) photoanodes immersed in natural Roselle and synthetic (N719) dyes for dye-sensitized solar cell (DSSC) application.
Design/methodology/approach
TiO2 mixed with rGO were doctor-bladed on fluorine doped tin oxide (FTO) glass substrate. The chemical and optical properties of TiO2/rGO photoanodes immersed in Roselle and N719 dyes were characterized using Fourier-transformed infrared (FTIR) and ultraviolet–visible (UV–vis) spectroscopies, respectively. The DSSC’s photovoltaic performances were tested using Visiontec Solar I-V tester at standard illumination of AM1.5 and irradiance level of 100 mW/cm2.
Findings
The presence of anthocyanin dye from Roselle flower was detected at 604 nm and 718 nm. TiO2/rGO+Roselle dye sample revealed the smallest energy gap of 0.17 eV for ease of electron movement from valence band to conduction band. The TiO2/rGO-based DSSC fabricated with Roselle dye had a power conversion efficiency, ƞ of 0.743 per cent higher than TiO2/rGO photoanode sensitized with N719 dye (0.334 per cent). The obtained J-V curves were analyzed by a single-diode model of Lambert W-function and manual optimization to determine the internal electrical parameters of the DSSC. The average and uncertainty values of Jsc and ƞ were evaluated at different Rsh range of 1362 Ω to 32 k Ω.
Research limitations/implications
Rs values were kept constant during optimization work.
Originality/value
New ideality factor of TiO2/rGO-based DSSC was re-determined around 0.9995.