Enhancement in the photostability of natural dyes for dye-sensitized solar cell (DSSC) applications: a review

Abstract

Summary The advancements in the generation of solar cells have created a landmark to design a cost‐effective, less weight, biocompatible, and environmental‐friendly solar cell. Dye‐sensitized solar cells (DSSCs) have become a topic of significant research in the recent years because of their imperative role in the zone of harvesting energy from the renewable source, and it appears to be a promising candidate for the triumph because of its low cost and ease of preparation. The use of synthetic dyes as a sensitizer for DSSC provides better efficiency and high durability. Unfortunately, they suffer from several margins such as higher cost and usage of toxic materials. These downsides have opened up for alternative sensitizer such as biocompatible natural dyes. Natural dyes contain plant pigments such as carotenoid, flavonoid, betalains, and chlorophyll that act as sensitizers (dye) for DSSC. But, the efficiency of natural dyes is not up to the mark mainly due to photoinstability of natural dye in the presence of sunlight that leads to photodegradation. The stability issues are mainly due to interaction of natural dyes with photoelectrode. The photoelectrodes in DSSC are semiconductor materials with superior characteristic of photocatalytic activity (PCA). The PCA of titanium dioxide (TiO2) generates high energetic free electrons on the surface of film that produce free radical ions in contact with moisture. These free radical ions readily degrade the organic matter present nearby (natural dye in DSSC). Thus, the PCA of photoelectrode is responsible for the photodegradation of dyes causing photoinstability. The main objective of this review is to study the photoinstability of natural dyes in DSSC. In this regard, the DSSC is concentrated into sections, and the stability issues due to PCA of photoelectrode are studied individually in the view of considering the DSSC operating with iodide‐based electrolytes and platinum as counter electrode only. Various algae groups are featured as a study tool to overview the dye interaction with photoelectrode. It highlights the application of Z‐scheme of photosynthesis to DSSC to have a broader perception on the working of DSSC and also shows some of the ways for improving the stability of dyes by suppressing or reducing the PCA of photoelectrode. Copyright © 2017 John Wiley & Sons, Ltd.

Low‐cost dye‐sensitized solar cells with ball‐milled tellurium‐doped graphene as counter electrodes and a natural sensitizer dye

“…The details of the characteristics of the produced cells are shown in the inset of Figure , and also in Table , with a comparison of a naturally (chlorophyll) sensitized cell by Chang et al The efficiency of the cell shows around 51% increase in the efficiency over a similarly sensitized cell. In general, the efficiency of cells sensitized by natural dyes is low (less than 1%) in most of the reviewed literature . The main advantage of the work reported here is twofold: First, the sensitizer is a nonfood material, and second, it is expected that the dyes extracted from the plants will change with seasons to control the amount of radiation absorbed by the plant (lighter dye colors in summer absorb less than richer colors in winter) and thus can mitigate efficiency loss due to heating in summer and due to lack of solar irradiation in winter.…”

“…In general, the efficiency of cells sensitized by natural dyes is low (less than 1%) in most of the reviewed literature. [37][38][39][40][41][42][43][44] The main advantage of the work reported here is twofold: First, the sensitizer is a nonfood material, and second, it is expected that the dyes extracted from the plants will change with seasons to control the amount of radiation absorbed by the plant (lighter dye colors in summer absorb less than richer colors in winter) and thus can mitigate efficiency loss due to heating in summer and due to lack of solar irradiation in winter.…”

Performance of the dye‐sensitized solar cells fabricated using natural dyes from Ixora coccinea flowers and Cymbopogon schoenanthus leaves as sensitizers

“…The DSSCs are a complex system which can directly convert the solar energy to electricity by sensitizing the wide‐band gap semiconductors . The DSSC has the advantage over common silicon solar cell that they can be produced from cost‐effective, nontoxic materials, thus making DSSC as the most suitable choice for dominance due to its easiness in preparation besides low in cost . However, in the recent years, DSSCs have gain the limelight of scientific research because of their important part in the field of harvesting energy from the renewable source .…”

“…The natural dye molecules in the DSSCs helped in developing this novel technology and decreased the costs of chemical synthesis and noble metals . However, photo degradation caused by the instability of natural dye in the presence of light had become the reason for the low efficiency of natural dye . Anthocyanin, chlorophyll, betalains, and carotenoid are the example of plant pigments that normally exist in natural dye and eventually act as sensitizers for DSSCs.…”

Three‐Component Activation/Alkynylation/Cyclocondensation (AACC) Synthesis of Enhanced Emission Solvatochromic 3‐Ethynylquinoxalines

“…Ta ilor-made fluorophores with designede mission characteristics have become increasingly important as functional constituents [1] in materials and life sciences, and their applicationsa re widespread, from organic electronics, [2] such as organic field effect transistors (OFETs), organic light-emitting diodes (OLEDs), and dye-sensitized solar cells (DSSCs), [3] to bioanalytical imaging ands ensing, [4] and diagnostics. [5] Fluorophores with color response to the surrounding media are particularly interesting.…”