As a result, natural dye-sensitized photovoltaic cells are formed to reduce the shortage of solar cell conversion efficiency. Compared to traditional solar cells, this photovoltaic cell has differential advantages, such as simple processing, often low cost, and integrates environmentally friendly materials. In addition, the use of synthetic dye as a photosensitizing agent such as N719 and Ru complex is a major disadvantage in DSSC. Such materials are highly effective, have incredible chemical stability and also have desirable photo-electrochemical characteristics. However, high fabrication cost due to complicated preparation methods and the presence of heavy metals that pose a threat to the environment, natural dyes were introduced in order to overcome these issues. Ruthenium additives are considered as extremely toxic and carcinogenic, which can spur to cancer. As a consequence, a number of studies have been conducted by many researchers to discover suitable alternative strategies for sensitizers in DSSC using natural pigment dyes such as anthocyanin, flavonoid and chlorophyll. Since natural dye has lower efficiency and stability, the varying thickness of metal oxide (ZnO) layer and paste has been studied to improve electrolyte performance and cell stability.