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

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 radic-chio have shown a monochromatic incident photon to current efficiency (IPCE) ranging from 40% to 69%. Short circuit photocurrent densities (J(sc)) up to 8.8 mA/cm(2), and open circuit voltage (V-oc) ranging from 316 to 419 mV, were obtained from these natural dyes under 100 mW/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. (C) 2012 Elsevier Ltd. All rights reserved.