Photoexcitations is a research area that explores the interactions between light and matter, specifically how molecules or materials absorb and emit light energy. This field of study focuses on understanding the electronic and optical properties of materials when they are excited by light, and how these interactions can be utilized in various applications such as photovoltaics, photocatalysis, and optoelectronics. Researchers in this field use techniques such as spectroscopy, microscopy, and computational modeling to study the dynamics of photoexcitations and their impact on the properties of materials.