Charge trap state occupation and energy level in individual CdSe/ZnS and CdSe/CdS core/shell quantum dots

Publication Type:

Miscellaneous

Source:

APS Meeting Abstracts, adsabs.harvard.edu (2010)

Keywords:

2010, 2013 and earlier

Abstract:

Quantum dot ``blinking'' is a widely observed but poorly understood phenomenon that degrades the performance of quantum dot-based
optoelectronic devices. It has been hypothesized that blinking is the
result of charge being trapped somewhere in or near the quantum dot, and
that this trapped charge prevents radiative recombination. To study charge
trapping, we use a scanning tunneling microscope to electrically probe
charge trap state occupation and energy level in individual CdSe/ZnS and
CdSe/CdS core/shell quantum dots. Our results indicate that quantum dots
can have both electron and hole trap states, and that the occupation of
these trap states can be manipulated using the STM. We additionally
comment on the location of the trapped charge by investigating quantum
dots with different shell thicknesses.