title: Anomalous photoluminescence in CdSe quantum-dot solids at high pressure due to nonuniform stress.
abstract: The application of static high pressure provides a means to precisely control and investigate many fundamental and unique properties of nanoparticles. CdSe is a model quantum-dot system, the behavior of which under high pressure has been extensively studied; however, the effect of nonuniform stresses on this system has not been fully appreciated. Photoluminescence data obtained from CdSe quantum-dot solids in different stress environments varying from purely uniform to highly nonuniform are presented. Small deviations from a uniform stress distribution profoundly affect the electronic properties of this system. In nonuniform stress environments, a pronounced flattening of the photoluminescence enegy is observed above 3 GPa. The observations are validated with theoretical calculations obtained using an all-atom semiempirical pseudopotential technique. This effect must be considered when investigating other potentially pressure-mediated phenomena.
authors.affiliation: Chemistry, Materials, Earth, and Life Sciences Directorate, Chemical Sciences Division, Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, CA 94551, USA. ahickey@unc.edu
authors.forename: Christian D
authors.initials: CD
authors.lastname: Grant
authors.forename: Jonathan C
authors.initials: JC
authors.lastname: Crowhurst
authors.forename: Sebastien
authors.initials: S
authors.lastname: Hamel
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Williamson
authors.forename: Natalia
authors.initials: N
authors.lastname: Zaitseva
mesh_terms: D019187:Cadmium Compounds / Q000737:chemistry*; D049449:Luminescence; D046529:Microscopy, Electron, Transmission; D010777:Photochemistry; D011312:Pressure; D045663:Quantum Dots; D018036:Selenium Compounds / Q000737:chemistry*
chemical_list: D019187:Cadmium Compounds; D018036:Selenium Compounds; C058667:cadmium selenide