Anomalous photoluminescence in CdSe quantum-dot solids at high pressure due to nonuniform stress

Small. 2008 Jun;4(6):788-94. doi: 10.1002/smll.200701097.

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.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Cadmium Compounds / chemistry*
  • Luminescence
  • Microscopy, Electron, Transmission
  • Photochemistry
  • Pressure
  • Quantum Dots*
  • Selenium Compounds / chemistry*

Substances

  • Cadmium Compounds
  • Selenium Compounds
  • cadmium selenide