Performance of dye extracts from the leaves of Tradescantia Pallida in a Dye-sensitized solar cell

Abstract

The performance of dye extracts from the leaves of tradescantia pallida in dye-sensitized solar cells (DSSC) has been investigated. The plant leaves were crushed into paste, and water was added in order to extract the dye. Fluorine-doped tin oxide (FTO) glass substrates were cleaned in an ultrasonic bath and then dried on a hotplate. Titanium dioxide (TiO2) paste was then uniformly deposited on the conducting side of one of the FTO glass substrates using a spatula. The FTO glass plate with the TiO2 paste deposit was annealed at about 450°C for 20 minutes to enhance the compactness of the deposit and to make it porous. This was then dipped in the dye to make the anode. Graphite was deposited on another FTO glass substrate using a pencil to make the counter electrode. DSSC was then fabricated by assembling the anode and the counter electrode together; an iodide electrolyte was then added in between them. Two multimeters, a variable resistor, and connecting wires were then connected in a circuit with the DSSC. While varying the resistance, the voltage and current were recorded with the incident light intensity set at 1000 Wm^(-2). The photovoltaic performance of the DSSC in terms of current, voltage, fill factor, maximum power, and efficiency was determined. The open circuit voltage, closed circuit current, maximum power, and fill factor were 0.449 V, 0.0999 mA, 0.03551 W, and 0.791, respectively. The efficiency of the solar cell was 0.0036%, a very low value that explains why DSSCs are not yet widely adopted but shows the potential of dye extract from tradescantia pallida for use as a sensitizer. The low efficiency could be due to the extraction technique used and the choice of the counter electrode. The performance of the DSSC can be enhanced by using a less viscous electrolyte, choosing a good counter electrode, and co-sensitizing. With the limited impacts on our surroundings and the relatively low production cost, this research has unfolded opportunities for the application of natural dyes from local sources in renewable energy solutions.