Silicon phthalocyanine dihydroxide is primarily utilized in the field of photodynamic therapy (PDT) for cancer treatment. Its ability to generate reactive oxygen species (ROS) upon exposure to light makes it an effective photosensitizer. When administered to a patient, it accumulates in tumor cells. Upon irradiation with a specific wavelength of light, it produces ROS that induce cellular damage, leading to the destruction of cancer cells. In addition to its role in cancer therapy, this compound is also explored for applications in organic photovoltaics. Its strong absorption in the visible and near-infrared regions enhances light harvesting in solar cells, improving their efficiency. The compound’s stability and electronic properties make it a promising candidate for use in next-generation photovoltaic devices. Furthermore, silicon phthalocyanine dihydroxide is investigated for its potential in antimicrobial photodynamic therapy (aPDT). It can be used to target and eliminate pathogenic microorganisms, including bacteria and fungi, when activated by light. This application is particularly valuable in treating infections that are resistant to conventional antibiotics. Its unique optical and electronic properties also make it suitable for use in sensors and imaging agents. It can be employed in fluorescence-based detection systems for biological and chemical analytes, providing high sensitivity and specificity. Overall, this compound demonstrates significant versatility across medical, energy, and sensing applications.