A near-infrared light emitting device can include semiconductor nanocrystals that emit at wavelengths beyond 1 .mu.m. The semiconductor nanocrystals can include a core and an overcoating on a surface of the core.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
 This invention was made with government support under Contract No. W911NF-07-D-0004 awarded by the Army Research Office and under Grant No. DE-SC0001088 awarded by the Department of Energy. The government has certain rights in the invention.