Eco-Friendly Dye-Sensitized Solar Cells Based on Water-Electrolytes and Chlorophyll

Ji-Hye Kim,Hyung-Jun Koo,Sung-Yoon Park,Dong-Hyuk Lim,So-Young Lim,Jonghoon Choi

doi:10.3390/ma14092150

Abstract

Organic solvents used for electrolytes of dye-sensitized solar cells (DSSCs) are generally not only toxic and explosive but also prone to leakage due to volatility and low surface tension. The representative dyes of DSSCs are ruthenium-complex molecules, which are expensive and require a complicated synthesis process. In this paper, the eco-friendly DSSCs were presented based on water-based electrolytes and a commercially available organic dye. The effect of aging time after the device fabrication and the electrolyte composition on the photovoltaic performance of the eco-friendly DSSCs were investigated. Plasma treatment of TiO2 was adopted to improve the dye adsorption as well as the wettability of the water-based electrolytes on TiO2. It turned out that the plasma treatment was an effective way of improving the photovoltaic performance of the eco-friendly DSSCs by increasing the efficiency by 3.4 times. For more eco-friendly DSSCs, the organic-synthetic dye was replaced by chlorophyll extracted from spinach. With the plasma treatment, the efficiency of the eco-friendly DSSCs based on water-electrolytes and chlorophyll was comparable to those of the previously reported chlorophyll-based DSSCs with non-aqueous electrolytes.

Highlights

We developed eco-friendly dye-sensitized solar cells (DSSCs) based on aqueous electrolytes and organic synthetic dyes
Instead of the typical DSSCs fabrication process, we introduced the dye into the electrolyte, i.e., dye-electrolyte, so that the dye molecules were adsorbed onto TiO2 via adsorption equilibrium
After 1 h of aging at room temperature, the efficiency of the eco-friendly DSSCs increased by 45%, from 0.044% to 0.064%

Summary

Introduction

Due to its advantages, such as a simple fabrication process, reasonable power conversion efficiency, and relatively low production cost [1,2], dye-sensitized solar cells (DSSC) have been actively researched for the past three decades. Even though the power conversion efficiency of the DSSCs reported is relatively low compared to the counterparts, e.g., perovskite and silicon solar cells [3,4,5], continuous efforts have still been made to improve the efficiency and replace the expensive noble metal catalysts with low-cost alternatives [6,7,8]. The enhanced photoconversion efficiency of DSSCs under ambient light was achieved, suggesting the potential of DSSCs for indoor applications [9]

Methods

Results

Conclusion