Use of residual purple sweet potato (Ipomoea batatas L.) skin pigment in dye-sensitized solar cells

Abstract

The objective of the following work is to study the usefulness of the pigment obtained from the peel of purple sweet potato to sensitize solar cells. Cells were built using ITO conductive sheets coated with a layer of TiO2 nanoparticles as a photoanode and carbon as a counter electrode, alcoholic purple sweet potato peel extract was prepared which was integrated into the TiO2 layer as dye-sensitizer. The performance of DSSCs was studied by irradiating them with light at different wavelengths with constant power. The electrochemical results show values of VOC = 0.374 V, JSC = 0.0244 mA/cm2, FF = 0.471 and an efficiency of 0.0143 % for when the cells were irradiated with 470 nm light. The EIS results confirm this performance by showing a low resistance to the flow of free charges under this wavelength. This work contributes to the use of organic waste material from purple sweet potato to obtain pigments and take advantage of their action in the operation of DSSCs.