Chapter 2: Fundamentals of Sunlight–Materials Interactions

This chapter focuses on the fundamental concepts and principles for sunlight–materials interactions. It starts with an introduction to solar energy and sunlight spectrum, with an emphasis on the generation and propagation of sunlight, followed by a discussion of the physical processes involved in light–matter interactions, including absorption, reflection, transmission, scattering, and luminescence. After that, the concept of quantum yield of solar energy conversion is introduced; in particular, examples of quantum yield in sunlight–materials interactions are discussed, such as in photocatalysis, photosynthesis, and photovoltaics. Other topics of merit for green nanostructured materials, including eco-friendliness and environmental sustainability, are also briefly discussed.