title: Visible emission characteristics from different defects of ZnS nanocrystals.
abstract: Various sized ZnS nanocrystals were prepared by treatment under H(2)S atmosphere. Resonance Raman spectra indicate that the electron-phonon coupling increases with increasing the size of ZnS. Surface and interfacial defects are formed during the treatment processes. Blue, green and orange emissions are observed for these ZnS. The blue emission (430 nm) from ZnS without treatment is attributed to surface states. ZnS sintered at 873 K displays orange luminescence (620 nm) while ZnS treated at 1173 K shows green emission (515 nm). The green luminescence is assigned to the electron transfer from sulfur vacancies to interstitial sulfur states, and the orange emission is caused by the recombination between interstitial zinc states and zinc vacancies. The lifetimes of the orange emission are much slower than that of the green luminescence and sensitively dependent on the treatment temperature. Controlling defect formation makes ZnS a potential material for photoelectrical applications.
authors.affiliation: State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, P. O. Box 110, Dalian 116023, China.
authors.forename: Xiuli
authors.initials: X
authors.lastname: Wang
authors.forename: Jianying
authors.initials: J
authors.lastname: Shi
authors.forename: Zhaochi
authors.initials: Z
authors.lastname: Feng
authors.forename: Mingrun
authors.initials: M
authors.lastname: Li
authors.forename: Can
authors.initials: C
authors.lastname: Li
mesh_terms: D003116:Color; D006358:Hot Temperature; D006862:Hydrogen Sulfide / Q000737:chemistry; D008163:Luminescent Measurements; D008958:Models, Molecular; D008968:Molecular Conformation; D049329:Nanostructures / Q000737:chemistry*; D055620:Optical Phenomena; D013057:Spectrum Analysis; D013440:Sulfides / Q000737:chemistry*; D013997:Time Factors; D017967:Zinc Compounds / Q000737:chemistry*
chemical_list: D013440:Sulfides; D017967:Zinc Compounds; C031238:zinc sulfide; D006862:Hydrogen Sulfide