Multi-level Oxygen Plasma Treatment Nanoarchitectonics on Chitosan/ PVA/TiO2 Composite-Based Absorber Layer Network for Efficient Polymer Solar Cells

Oxygen (O2) plasma surface treatment provides an effective approach for increasing the amount of active absorption sites on the surface of a Chitosan-based active layers (ALs), opening up opportunities for efficient organic solar cells. For the first time, distinct in-situ O2 plasma dosages (0, 2, 4, 6, and 8 min) were applied to the newly developed ALs of Chitosan/PVA/TiO2 (CPT) to optimize their microstructural and physiochemical characteristics. The untreated cell (FTO|Al2O3/CPT(0 min)/TiO2-gel/electrolyte |Ag) has the smallest Jsc (14.2 mA/cm2) and power conversion efficiency (PCE) of 4.5%. PCE and Jsc increased to 5.14% and 15.6 mA/cm2
, respectively, every time the CPT AL was treated with plasma dose for 2 minan d then exposed to the generated cell FTO|Al2O3/CPT (2 min)/TiO2-gel/electrolyte |Ag. On the other hand, by creating an environment that promotes charge separation, integrating high-energy plasma ions increased the mobility of charge carriers in Chitosan/PVA alloys while decreasing their recombination. Extended lifespans and improved charge transfer inside photovoltaic (PV) cells are thereby achieved through improved mobility and reduced resistive losses. Accordingly,after 6 min of plasma treatment in the intended cell of FTO|Al2O3/CPT(6 min)/TiO2-gel/electrolyte |Ag, the optimized PCE of 7.6% and Jsc of 19.1 mA/cm2 were reached. The PCE increase equated to a 40.8% growth above a pure one.
The increased electron transfer inside the hybrid was attributed to the suffusing amount of plasma radicals that formed
the connecting channels of the Chitosan/PVA system, consequently elevating PV performance. Continuous improvements
in PSCs development and incorporation into energy systems will enable a more resilient and sustainable energy future.