Scanning tunneling microscopy and UV-visible spectroscopy studies of lead sulfide ultrafine particles synthesized in Langmuir-Blodgett films

Ultrafine semiconductor particles of lead sulfide were synthesized by exposing lead stearate Langmuir-Blodgett films to hydrogen sulfide gas. By heating the Langmuir-Blodgett films containing PbS ultrafine particles in nitrogen gas at 120 o C for 1 h, the molecules of stearic acid were evaporated and the lead sulfide particles were left. The PbS ultrafine particles before and after evaporation were analyzed by using a scanning tunneling microscope and a UV-visible spectrophotometer