Anomalous photoluminescence in CdSe quantum-dot solids at high pressure due to nonuniform stress.
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.
Grant
Christian D
CD
Chemistry, Materials, Earth, and Life Sciences Directorate, Chemical Sciences Division, Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, CA 94551, USA. ahickey@unc.edu
Crowhurst
Jonathan C
JC
Hamel
Sebastien
S
Williamson
Andrew J
AJ
Zaitseva
Natalia
N
D019187:Cadmium Compounds / Q000737:chemistry*; D049449:Luminescence; D046529:Microscopy, Electron, Transmission; D010777:Photochemistry; D011312:Pressure; D045663:Quantum Dots; D018036:Selenium Compounds / Q000737:chemistry*
D019187:Cadmium Compounds; D018036:Selenium Compounds; C058667:cadmium selenide