Absorption Analysis of Photosystem I in Different Plants for Biohybrid Solar Cell Applications

Biohybrid solar cells, which are inspired by photosynthesis process in plants, are new low‐cost and environmentally friendly solar cells. In this kind of solar cells, photosystem I (PSI), which is the main part of photosynthesis process, is used as light absorber layer. Herein, PSI is extracted from some easily accessible plants, including spinach, Tung‐Oh, chye sim, local endive, beet greens, leek, Swiss chard, and romaine lettuce, and their light absorbance properties are studied. It is shown that the optical bandgap of PSI extracted from all of these plants is about 1.8 eV which indicates the potential of these plants for use in biohybrid solar cells. It is shown that, due to the higher light absorbance, spinach is the best plant for this kind of solar cells. Also, the effect of temperature on light absorbance of PSI extracted from spinach is investigated and shows that the light absorbance of PSI considerably decreases at high‐temperature values. Furthermore, alkaline and acidic environments on PSI light absorbance are studied and shows that the alkaline pH stress has no destructive effect on light absorbance, while the acidic pH stress causes a considerable decrease in light absorbance which is important in biohybrid solar cell fabrication.