title: A study on fabrication, morphological and optical properties of lead sulfide nanocrystals.
abstract: To investigate the properties of lead sulfide (PbS) nanocrystals, we have prepared PbS nanocrystals on/in the porous alumina membrane with a pore diameter 20 nm. Utilizing the reaction of Pb wires and the hydrogen sulfide (H2S) gas, PbS nanocrystals produced and grew as the reaction time increased. The composition identification of the nanocrystals was performed by the XPS and EDS analyses. More structure characteristics of the PbS nanocrystals obtained from the TEM analysis. As indicated in the PL spectra, an orange-red emission band appeared and the emission intensities were obviously related to the defects in the nanocrytals. A significant quantum confinement effect made the energy gap of PbS nanocrystals produce a blue shift from 0.41 eV to 1.89 eV. Furthermore, the growth mechanism of the PbS nanocrystals was also discussed.
authors.affiliation: Department of Materials Science and Engineering, National Chiao Tung University, Hsinchu, Taiwan 300, Republic of China.
authors.forename: Jung-Hsuan
authors.initials: JH
authors.lastname: Chen
authors.forename: Shen-Chuan
authors.initials: SC
authors.lastname: Lo
authors.forename: Chuen-Guang
authors.initials: CG
authors.lastname: Chao
authors.forename: Tzeng-Feng
authors.initials: TF
authors.lastname: Liu