The influence of microbial sources on astaxanthin implementation as sensitizer in dye sensitized solar cells (DSSCs)

• microbial astaxanthin implementation for third generation photovoltaic devices development. • competitive energy supplier improved by fermentation chemistry. • Paracoccus carotinifaciens biomass extract used as innovative photosensitizer. In the context of increasing the use of sustainable materials derived from renewable, non-toxic, and biocompatible sources, dyes obtained from microorganisms have garnered significant interest, particularly for clean energy applications. This study presents a novel comparison of astaxanthin produced from three different microbial sources for dye-sensitized solar cells (DSSCs) to evaluate their photovoltaic performance. Comprehensive characterization using multiple analytical techniques (HPLC-DAD-APCI-MS, UV–vis spectroscopy, scanning electron microscopy (SEM), IV measurements, and electrochemical impedance spectroscopy (EIS)) were carried out on pigments extracted from the microalga Haematococcus pluvialis , the yeast Phaffia rhodozyma , and the bacterium Paracoccus carotinifaciens to highlight the structural differences that influence the dyes’ photoelectrochemical behavior. The results show that the DSSC based on the extract from Paracoccus carotinifaciens demonstrated the highest efficiency, recording a short-circuit current density (Jsc) of 2.86 mA/cm 2 , an open-circuit voltage (Voc) of 0.419 V, a fill factor (FF) of 0.3, and a power conversion efficiency (PCE) of 0.36 %.