Nanotechnology · 2004 · 55 citations · 20 references
Natural SciencesMaterials EngineeringMaterials ScienceNanotechnologySemiconductor MaterialsThin FilmsLuminescent MaterialsOptical Properties Of SemiconductorsOptical Thin FilmsQuantum DotsSemiconductor NanomaterialsThin Film Optical PropertiesAuger IonizationAuger RecombinationDigital Data StorageLight IntensityLuminescent NanomaterialsOptoelectronic PropertiesPhotoluminescencePhotoluminescence Spectroscopy
We report that the storage and clearing of multi-digital data, that is, the photoluminescence (PL) intensity of CdSe/ZnS core/shell nanocrystal (NC) thin film, can be operated by a single excitation wavelength. First, a 7.4 µm-square area on the NC film was irradiated by strong light ranging in intensity from 2.64 to 1370 nW. Then, a 60 µm-square area including the pre-irradiated region was scanned with weak light (about 0.6 nW) to visualize the PL intensity difference between pre- and non-irradiated regions (I and I0, respectively). The normalized PL intensity, I/I0, increased with total pre-irradiation energy, until reaching saturation. The level of I/I0 at which the PL intensity becomes saturated reversibly increased with decreasing light intensity at pre-irradiation. The results imply that Auger ionization becomes dominant and suppresses the enhancement of the emission efficiency with higher irradiation intensities.
20
Fluorescence intermittency in single cadmium selenide nanocrystals
M. Nirmal, B. O. Dabbousi, Moungi G. Bawendi et al. · Nature · 1996 · 2K citations