Excitons in nanoscale systems

A cross-disciplinary review of the characteristic features of excitons in nanoscale system is presented. The review covered several topics including confinement effects, localization versus delocalization, exciton binding energy, exchange interactions, and exciton fine structures, exciton-vibration coupling, and dynamic of excitons. Excitons in nanoscale systems are formed by light absorption in molecules such as polyacenes and polyones, conjugated polymers, quantum dots, molecular aggregates, and carbon nanotubes. Conjugated polymer excitons play important roles in electroluminescent and photovoltaic devices, and some intriguing properties relevant to device optimization. Interesting spectroscopic properties of excitons, which are often miniscule in bulk materials, are also greatly accentuated in nanometer-sized materials and molecules.