Quantum yield determination involves assessing the efficiency of a photochemical process. It represents the ratio of the number of photons emitted through photoluminescence, or the number of molecules reacted in a photochemical reaction, to the number of photons absorbed by the system. For example, a quantum yield of 0.5 indicates that for every two photons absorbed, one photon is emitted, or one molecule undergoes the desired photochemical transformation. Different methods exist for these measurements, depending on the specific process being studied, ranging from simple comparative techniques to absolute measurements using integrating spheres.
This efficiency metric plays a crucial role in various fields, including photochemistry, materials science, and solar energy research. Understanding and optimizing this ratio are essential for developing more efficient light-emitting devices, such as LEDs and lasers, and for improving the performance of solar cells and photocatalysts. Historically, early investigations into the interaction of light and matter laid the foundation for this concept, contributing to our understanding of fundamental photophysical processes. The ability to quantify these processes provides valuable insights into the behavior of excited-state molecules and materials.
