A population of nanoparticles is disclosed. The population is comprised of a plurality of core/shell nanocrystals, each including: a semiconductor core, an intermediate semiconductor shell layer disposed over the semiconductor core, an external semiconductor shell layer disposed over the intermediate semiconductor shell layer, and a hydrophilic organic layer in direct contact with the external semi-conductor shell layer. The population of nanoparticles has a αon value of less than about 1.4.