A bacteriorhodopsin-based biohybrid solar cell using carbon-based electrolyte and cathode components

Area of Science:

• Renewable Energy Technologies
• Materials Science
• Biophysics

Background:

• Global demand for sustainable energy drives research into novel solar cell technologies.
• Bio-sensitized solar cells (BSCs) offer promising optical and photoelectrical properties.
• Bacteriorhodopsin (bR), a stable and efficient photoactive protein, is a key biosensitizer candidate.

Purpose of the Study:

• To develop and characterize a bio-based solar cell using a mutant bacteriorhodopsin (D96N) as a photosensitizer.
• To integrate low-cost, carbon-based components for the photoanode, cathode, and electrolyte.
• To evaluate the electrochemical performance and efficiency of the novel bio-sensitized solar cell.

Main Methods:

• Fabrication of a photoanode-sensitized TiO2 solar cell utilizing D96N bacteriorhodopsin.
• Construction of a cathode using PEDOT functionalized with multi-walled carbon nanotubes (CNT).
• Electrochemical characterization using linear sweep voltammetry (LSV), open circuit potential decay (VOC), and impedance spectroscopy (EIS).

Main Results:

• The champion device achieved a current density (JSC) of 1.0 mA/cm², a VOC of -669 mV, and a fill factor of ~24%.
• The power conversion efficiency (PCE) of the bio-sensitized solar cell was determined to be 0.16%.
• Morphological and chemical characterization of photoanode and cathode were performed using SEM, TEM, and Raman spectroscopy.

Conclusions:

• This work presents one of the first bio-based solar cells employing carbon-based alternatives for key components.
• The developed bacteriorhodopsin-based solar cell demonstrates potential for reduced manufacturing costs.
• The integration of bio-based and carbon materials significantly enhances the sustainability of solar energy devices.