Anthocyanins and betalains as light-harvesting pigments for dye-sensitized solar cells

Abstract

We present the photoelectrochemical properties of dye-sensitized solar cells using natural pigments containing betalains and anthocyanins as sensitizers. The dyes extracted from grape, mulberry, blackberry, red Sicilian orange, Sicilian prickly pear, eggplant and radicchio have shown a monochromatic incident photon to current efficiency (IPCE) ranging from 40% to 69%. Short circuit photocurrent densities (J sc) up to 8.8mA/cm 2, and open circuit voltage (V oc) ranging from 316 to 419mV, were obtained from these natural dyes under 100mW/cm 2 (AM 1.5) simulated sunlight. The best solar conversion efficiency of 2.06% was achieved with Sicilian prickly pear fruits extract. The influence of pH and co-absorbers on natural sensitizers, were investigated and discussed. © 2012 Elsevier Ltd.