Abstract

Semiconductor nanocrystals that are smaller than the bulk exciton exhibit novel properties resulting from the three-dimensional quantum confinement,¹ Figure 1 shows the linear absorption of three sizes of CdSe nanocrystals used in our study. These samples are grown in high-temperature trioctylphosphine oxide, precipitated in methanol, and embedded in ~100-μm free-standing polymer (PVB) film. This new growth technique yields a particle size distribution that is considerably narrower than that achievable by other methods, As a result, the lowest-energy (HOMO-LUMO) transition is clearly distinguished from the higher-lying transitions. The residual linewidth arises primarily from small variations (±2 Å) in the particle diameter.

© 1993 Optical Society of America