The nondestructive observation of correlation between optical characteristic and morphologic feature within capped ZnCdSe/ZnSe quantum dots system

• The coexistent dense QDs and atypical 2D structures are identified nondestructively.
• The different lateral exciton migration modes are demonstrated.
• The correlation between optical feature and morphologic characteristic is analyzed.

The correlation between optical property and morphologic appearance within capped ZnCdSe/ZnSe quantum dots (QDs) system is investigated by photoluminescence (PL) spectrum measured at temperatures from 11 to 300 K. The coexistent dense QDs and atypical two-dimensional non-uniform structures (neither wetting layer nor small platelet) are identified by their unique temperature evolutions of full width at half maximum (FWHM), distinct quenching rates of spectral integrated intensity and extra redshifts of emission peak energy. The divergent lateral exciton transfer modes between these two quantum structures are demonstrated by the differently morphologic-induced spectral features. The incompletely three-dimensional excitonic confinement within QDs assemblies is observed by comparing the carrier repopulation-induced redistribution of emission energy with that of isolated QDs system. In comparison with general surface detection methods of the uncapped sample, utilizing PL as spectral probe is a nondestructive technique to explore inner morphologic characteristics of capped multiple quantum structure within functional device.

The comparison of different declines in temperature evolutions of emission peak energy of laterally coupled quantum dots, atypical two-dimensional non-uniform structures and isolated quantum dots. Figure optionsDownload as PowerPoint slide