title: Stability study of PbSe semiconductor nanocrystals over concentration, size, atmosphere, and light exposure.
abstract: Infrared-emitting PbSe nanocrystals are of increasing interest in both fundamental research and technical application. However, the practical applications are greatly limited by their poor stability. In this work, absorption and photoluminescence spectra of PbSe nanocrystals were utilized to observe the stability of PbSe nanocrystals over several conventional factors, that is, particle concentration, particle size, temperature, light exposure, contacting atmosphere, and storage forms (solution or solid powder). Both absorption and luminescence spectra of PbSe nanocrystals exposed to air showed dependence on particle concentration, size, and light exposure, which caused large and quick blue-shifts in the optical spectra. This air-contacted instability arising from the destructive oxidation and subsequent collision-induced decomposition was kinetically dominated and differed from the traditional thought that smaller particles with lower concentrations shrank fast. The photoluminescence emission intensity of the PbSe nanocrystal solution under ultraviolet (UV) exposure in air increased first and then decreased slowly; without UV irradiation, the emission intensity monotonously decreased over time. However, if stored under nitrogen, no obvious changes in absorption and photoluminescence spectra of the PbSe nanocrystals were observed even under UV exposure or upon being heated up to 100 degrees C.
authors.affiliation: Department of Chemistry and Biochemistry, Worcester Polytechnic Institute, 100 Institute Road, Worcester, Massachusetts 01609, USA.
authors.forename: Quanqin
authors.initials: Q
authors.lastname: Dai
authors.forename: Yingnan
authors.initials: Y
authors.lastname: Wang
authors.forename: Yu
authors.initials: Y
authors.lastname: Zhang
authors.forename: Xinbi
authors.initials: X
authors.lastname: Li
authors.forename: Ruowang
authors.initials: R
authors.lastname: Li
authors.forename: Bo
authors.initials: B
authors.lastname: Zou
authors.forename: JaeTae
authors.initials: J
authors.lastname: Seo
authors.forename: Yiding
authors.initials: Y
authors.lastname: Wang
authors.forename: Manhong
authors.initials: M
authors.lastname: Liu
authors.forename: William W
authors.initials: WW
authors.lastname: Yu
mesh_terms: D000042:Absorption; D000388:Air; D001272:Atmosphere; D003624:Darkness; D007854:Lead / Q000737:chemistry*; D008027:Light; D053758:Nanoparticles / Q000737:chemistry*; D009584:Nitrogen / Q000737:chemistry; D010316:Particle Size; D018036:Selenium Compounds / Q000737:chemistry*; D012666:Semiconductors; D012996:Solutions; D013997:Time Factors; D014466:Ultraviolet Rays
chemical_list: D018036:Selenium Compounds; D012996:Solutions; C088065:lead selenide; D007854:Lead; D009584:Nitrogen