Synthesis of PbS Semiconductor Microcrystallites In Situ in Reverse Micelles

ABSTRACTColloid semiconductor particles of PbS have been prepared in reversed micelles of AOT-heptane. The effects of the AOT, water and reactants concentrations have been studied. The initial crystallite size and its growth with the time aging are strongly dependent on the water/AOT ratio and the ionic pool concentration. The absorption spectroscopic characteristics of the PbS particles have been examined. As the particle size decreases the band gap shifts in color from orange-brown to yellow and approaches the transition energy of the first allowed excited state of a PbS molecule. Moreover, the optical nonlinear property of PbS particles was investigated by Degenerate Four-Wave Mixing (DFWM) experiment using a frequency-doubled Nd:YAG laser.