Photodegradation in quantum dots (QDs) is a process where their optical and electronic properties degrade under prolonged exposure to light.

Photodegradation in quantum dots (QDs) is driven by multiple interconnected factors, including material composition, environmental conditions, light exposure parameters, and reactive species. The intrinsic properties of QDs, such as their core/shell structure and surface ligands, play a critical role in stability. For instance, unprotected cores (e.g., CdSe) degrade faster than those with robust shells (e.g., ZnS-coated QDs), while weakly bound ligands (e.g., oleic acid) can desorb under light, exposing the QDs to damage. Environmental conditions like oxygen and moisture accelerate oxidation and hydrolysis, leading to surface defects and emission loss. Light exposure parameters, including wavelength, intensity, and duration, directly influence degradation rates—UV light and high intensities generate excess excitons and reactive oxygen species (ROS) such as •OH and •O₂⁻, which attack the QD surface. Thermal effects from prolonged irradiation further destabilize the structure. To mitigate degradation, strategies include using inert shells, stable ligands (e.g., PEG), operating in oxygen-free environments, and optimizing light conditions. If needed, advanced characterization techniques like photoluminescence spectroscopy or TEM can track degradation mechanisms.