Photophysical behavior of ultrasmall CdSe semiconductor particles in a perfluorosulfonate membrane

Abstract

Ultrasmall CdSe semiconductor particles that exhibit size quantization effects are prepared in a perfluorosulfonate membrane (Nafion) by exposing Cd²⁺-exchanged film to H₂Se. The growth of the particle can be controlled by varying the reaction time or the concentration of Cd²⁺ in the Nafion film. CdSe particles exhibit an emission maximum in the region of 560-600 nm, the position of the maximum being dependent on the particle size. The emission decay is multi-exponential with lifetimes ranging into the nanosecond time regime. The photophysical behavior of CdSe particles in Nafion has also been probed with picosecond laser flash photolysis.