When small is different: Some recent advances in concepts and applications of nanoscale phenomena

Reduction in size often does more than simply make things smaller There are many properties of materials that undergo qualitative, often sudden, changes below a certain size scale. This Report first describes some of these size-dependent properties. Following this general description, recent developments in a number of selected topics in nanoscience are covered. These topics are: luminescence from Au nanoparticles; Si (and related) nanoparticle luminescence; modification of optical absorption by surface adsorption on nanoparticles; and transistors (and some other devices) based on nanotubes and nanowires.