Polymers enable flexible, lightweight solar cells with >18% efficiency. Encapsulants boost UV and moisture resistance. Self-cleaning coatings retain 95% output, and stretchable polymers allow wearable modules with up to 50% strain.

We present a cost-effective approach for converting petroleum coke into high-quality graphene via thermal desulfurization followed by electrochemical exfoliation. The synthesized graphene exhibited structural integrity and optoelectronic properties comparable to those of graphite-derived materials. Integrated as rear electrodes in perovskite solar cells (PSCs), the petcoke-derived graphene enabled devices to achieve a power conversion efficiency (PCE) of approximately 19.1%, with an open-circuit voltage (V_oc) exceeding 1.13 V and a fill factor (FF) of ∼78%. The petcoke-derived graphene PSCs exhibited superior photovoltaic performance compared to those fabricated with commercial graphene, and demonstrated comparable efficiency to devices employing conventional gold electrodes. These findings highlight the potential of waste-derived graphene as a scalable, sustainable, and economically viable alternative to noble metal contacts, aligning with circular economy principles and advancing low-cost photovoltaic technologies.

This study presents an effective strategy to enhance the efficiency and stability of perovskite solar cells (PSCs) by integrating neodymium-doped upconversion nanoparticles (UCNPs) coated with a TiO₂ shell into the mesoporous electron transport layer. The incorporation of neodymium (Nd³⁺) as a novel sensitizer shifts the near-infrared (NIR) absorption band away from the water vapor absorption region in the solar spectrum. This modification enables UCNPs to efficiently convert NIR light into ultraviolet (UV) and blue wavelengths, which are readily absorbed by TiO₂, generating additional charge carriers and improving photovoltaic performance. The optimized PSCs, fabricated by blending 30% UCNPs@TiO₂ with commercial TiO₂ paste, achieved a peak power conversion efficiency (PCE) of 21.71%, representing a 20.4% improvement over the control (18.04%). This enhancement included a 0.9% increase in the open-circuit voltage (V_oc), a 6.6% rise in the short-circuit current density (J_sc), and an 11.9% boost in the fill factor (FF). Additionally, the optimized PSCs exhibited remarkable stability, retaining over 90% of their initial PCE after 900 h in humid conditions, compared to only 70% for the control. These improvements result from enhanced light absorption, reduced moisture infiltration, and lower defect-related recombination. This approach provides a promising pathway for developing highly efficient and durable PSCs.

In alignment with Saudi Arabia’s Vision 2030, the Kingdom aims to achieve one of its main environmental targets: reaching net zero emissions by 2060. This ambitious goal can be realized through Carbon Dioxide Removal (CDR) technologies, particularly Direct Air Capture (DAC), which is among the most promising solutions. DAC offers high potential for extracting Carbon Dioxide (CO₂) directly from the atmosphere and is considered sustainable, especially when powered by renewable energy rather than fossil fuels. However, the technology remains highly cost-intensive. This paper presents a techno-economic assessment of renewable energy configurations to determine the most cost-effective solutions for DAC deployment. The evaluation focuses on Net Present Cost (NPC) and Levelized Cost of Energy (LCOE) across several regions in Saudi Arabia, using the Hybrid Optimization of Multiple Energy Resources (HOMER) Pro software (version 3.18.4).