Observation of emissions from CdSe single quantum dots and spatial mapping by micro-cathodoluminescence measurement

Single quantum dots (QD) luminescence from MBE-grown CdSe/ZnSe QD was observed by micro-cathodoluminescence measurement. The scanning area of the exciting electron beam was decreased from 100 × 100 μm2 to 0.2 × 0.2 μm2. A broad emission was observed till an area of 2 × 2 μm2, and sharp emission lines were clear at a scanning area of 1 × 1 μm2 or less. The spatial resolution of this measurement was determined to be 0.45 μm from the number of sharp lines and the QD density. The luminescence intensity mapping was performed at arbitrarily selected wavelengths, and QD existence was clearly shown at different positions at each wavelength. Thus, the luminescence observation of the CdSe single QD and its mapping were successfully performed by micro-cathodoluminescence measurement for the first time. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)