Improved lifespan of photovoltaic devices based on ZnO nanorods/p-silicon heterostructures using active air convection cooling systems: a comparative degradation study

Nanostructured solar cells offer substantial advantages in terms of material efficiency and streamlined fabrication techniques; however, their operational reliability at elevated temperatures remains a critical challenge. This study, for the first time, evaluates the influence of forced air convection cooling on the operational longevity and stability of nanostructured heterojunction photovoltaic devices fabricated on zinc oxide nanorods. Here, a ZnO buffer layer was initially deposited to form a heterojunction with Si substrate, followed by the development of zinc oxide nanorods designed to enhance photon absorption. Two identical solar cells were fabricated and subjected to continuous solar irradiation for 30 days; one was actively cooled using a forced air system, while the other was left uncooled. Post-exposure characterization proved that the morphology and optical characteristics of the cooled nanorods remained largely intact, underscoring the significance of thermal management in maintaining the performance of nanostructured photovoltaic devices. The reference cells without cooling exhibited a 7.4% efficiency loss after 30 days of continuous operation, due to elevated temperatures causing structural changes in the ZnO nanorods. The fan-cooled devices maintained more stability during the same period, with a 2.0% decrease in efficiency. The microstructural evaluation of cooled devices revealed that their nanorod structure remained intact with minimal damage. The results showed that heat management strategies enhance the reliability and operational lifespan of nanostructured photovoltaic devices.