Improving the efficiency of polymer solar cells based on chitosan@PVA@rGO composites via gamma-irradiated treatment of rGO nanoparticles

Polymer solar cells (PSCs) are growing as attractive contenders for renewable energy technologies given their
low cost, adaptability, and environmental sustainability, rendering them valuable in combating climate change.
Interestingly, this work investigates the augmentation of photon absorption and overall efficiency in low-cost,
effective active layers (ALs) via gamma irradiation treatment, thereby raising the number of active absorption
sites. For the first time, novel Chitosan@PVA@rGO (CPG) composite sheets were created as AL materials and
treated to varied dosages of in-situ gamma irradiation (0, 10, 20, 30, and 40 KGy) to optimize their micro
structural and physicochemical characteristics. The processed ALs were subjected to comprehensive tests, which
included J–V variable evaluation as well as evaluations of microstructure, porosity, morphology, contact angle,
optical characteristics, and electrochemical impedance spectroscopy (EIS). The findings reveal that the com
posites’ surface properties got better gradually as gamma irradiation dosages grew; peak performance was
reached at 30 KGy (75.9 % apparent porosity and roughness parameter Ra = 6.22 μm). Extended gamma irra
diation resulted in increased DSSC efficiency, which reached 6.85 % after 10 KGy and 7.63 % after 20 KGy. Highenergy gamma photons boosted mobility and decreased resistive limits by reducing carrier recombination and
facilitating charge carrier movement inside CPG compounds. This increased the longevity and charge transfer
efficiency of the solar cell. After 30 KGy alteration, the CPG AL’s optimized efficiency of 8.78 % and Jsc of 20.23
mA/cm2 indicate a 44.3 % improvement in efficacy over the pristine material. The insertion of oxygen-enriched
free radicals into the CPG structure is responsible for the improvement in photovoltaic efficiency because it
creates continuous pathways for fast electron transport. This work provides an innovative perspective on the use
of heteroatom-doped ALs in PSCs by highlighting the benefits of co-doping and regulated heteroatom species