Single Quantum Dots

tl_files/mona/images/Quantum Dots/ConfocalSetup.pngSemiconductor nanocrystals are efficient and tunable light sources due to quantum size effects. One of their surprising and still puzzeling properties can be observed on a single particle level. This is the so called blinking - a random switching behavior between an emitting an non-emitting state. It is the aim of the groups research to characterize the photophysical properties of quantum dots and to control their light emission, especially their blinking behavior.





Dynamics of colloidal quantum dots in electric fields

tl_files/mona/images/Quantum Dots/VoltageScan.pngThe emission intermittency of single quantum dots is supposed to be related to Auger effects in the quantum do core. These Auger effects involve the transfer excitation energy from a generated exciton to a free charge in the core. This requires that the two charges of an exciton are eventually separated to leave a charge quantum dot behind. We study the charge state of colloidal quantum in nonpolar solvents by recording their migration in external electric fields.