Metal-pigment complex derived from natural dye of anthocyanin: a potential candidate for DSSC photosensitizer

摘要

This research is aimed to synthesize iron-pigment complex of anthocyanin extracted from the peel of red dragon fruit(Hylocereus polyrhizus).The targeted iron-complex was then evaluated to confirm its potential use as photosensitizer on Dye Sensitize Solar Cell(DSSC).The electronic absorption spectrum of the red dragon fruit extract showed a broad band spanning from 400 nm to 600 nm and a band maximum at 533 run.This band was then evaluated to find out the energy of electronic transition;an excitation from highest occupied molecular orbital(HOMO;valence band)toward lowest unoccupied molecular orbital(LUMO;conduction band).The calculation resulted in the equivalent energy level of 1.98 eV for HOMO,and 4.48 eV.These values represent the energy gap(Eg)for sensitizer on DSSC.Furthermore,evaluation of electronic transition of iron complex reveals that there is an increase of absorption coverage range,due in particular the blue shift of the conduction band.These characteristics are supporting evidences that the iron-anthocyanin complex is a good candidate for sensitizer of DSSC.