Structure and Photoelectrical Properties of Natural Photoactive Dyes for Solar Cells

Qian Liu,Dejiang Liu,Nan Gao,Yuanzuo Li,Jinglin Liu

doi:10.3390/app8091697

Abstract

A series of natural photoactive dyes, named as D1–D6 were successfully extracted from six kinds of plant leaves for solar cells. The photoelectrical properties of dyes were measured via UV-Vis absorption spectra, cyclic voltammetry as well as photovoltaic measurement. To theoretically reveal the experimental phenomena, the chlorophyll was selected as the reference dye, where the ground and excited state properties of chlorophyll were calculated via density functional theory (DFT) and time-dependent density functional theory (TD-DFT). The experimental results show that the absorption peaks of those dyes are mainly distributed in the visible light regions of 400–420 nm and 650–700 nm, which are consistent with the absorption spectrum of chlorophyll. The photoelectrical conversion efficiencies of the solar cells sensitized by the six kinds of natural dyes are in the order of D1 > D4 > D2 > D5 > D6 > D3. The dye D1 performance exhibits the highest photoelectrical conversion efficiency of 1.08% among the investigated six natural dyes, with an open circuit voltage of 0.58 V, a short-circuit current density of 2.64 mA cm−2 and a fill factor of 0.70.

Highlights

With the development and utilization of renewable energy, much works have been paid attention to the devices converting solar energy into electrical energy, among which the dye-sensitized solar cells (DSSCs) with its characteristics of low fabrication costs, environmentally friendly components and relatively high photoelectrical conversion efficiency (PCE) have received wide attention [1,2,3,4,5].In 1991, Regan and Gratzel [6] created the DSSCs with overall PCE yield of 7.1–7.9% in simulated solar light from low- to medium-purity materials by low-cost process
Qin et al [41] reported a theoretical study of the betalain pigments using density functional theory (DFT) and time-dependent density functional theory (TD-DFT), and the results indicated that the lowest unoccupied molecular orbital (LUMO) had a close spatial proximity to bound TiO2, assuming that betalain binding occured through the two carboxylic groups on the dihydropyridine ring
To compare with the experimental results, the chlorophyll was selected as the reference molecule, and the ground and excited state properties of chlorophyll were calculated via DFT and TD-DFT methods, respectively

Summary

Introduction

With the development and utilization of renewable energy, much works have been paid attention to the devices converting solar energy into electrical energy, among which the dye-sensitized solar cells (DSSCs) with its characteristics of low fabrication costs, environmentally friendly components and relatively high photoelectrical conversion efficiency (PCE) have received wide attention [1,2,3,4,5].In 1991, Regan and Gratzel [6] created the DSSCs with overall PCE yield of 7.1–7.9% in simulated solar light from low- to medium-purity materials by low-cost process. With the development and utilization of renewable energy, much works have been paid attention to the devices converting solar energy into electrical energy, among which the dye-sensitized solar cells (DSSCs) with its characteristics of low fabrication costs, environmentally friendly components and relatively high photoelectrical conversion efficiency (PCE) have received wide attention [1,2,3,4,5]. Researchers have found that the application of natural dyes extracted from the plant flowers petals, leaves, roots in the DSSCs, producing a considerable PCE [20,21,22,23,24,25,26,27,28,29,30,31,32,33], which has opened up a friend way for the conversion of solar energy into electricity.

Methods

Results

Conclusion