This book is a collection of many of the papers presented at the Fourth International Symposium on Quantum Confinement: Nanoscale Materials, Devices, and Systems, held May 4-7 in Montreal, Canada, as part of the 191st Meeting of the Electrochemical Society. The symposium was sponsored by the Dielectric Science and Technology, the Electronics, and the Luminescence and Display Materials divisions of the Electrochemical Society. The symposium was organized into 8 sessions of oral presentations over a period of three days to address recent advances in nanoscale and quantum confined structures, including chemistry of nanostructures, growth and characterization of nanocrystals, optical and electrical properties of quantum dots, wires, and nanocrystals, and transport in quantum wires and devices.