Title :
Luminescence spectrum analysis of CdSe/CdS core/shell quantum dots prepared by ultrasonic irradiation
Author :
Limin An ; Yuqiu Qu ; Xue Dong ; Jintao Zhang ; Shengchun Liu
Author_Institution :
Coll. of Phys. Sci. & Technol., Heilongjiang Univ., Harbin, China
Abstract :
The steady-state and time-resolved luminescent properties of CdSe/CdS core/shell quantum dots are discussed. A combination of UV-Visible absorption spectroscopy photoluminescence (PL) spectroscopy and up-conversion luminescence is employed to analyze the optical characters. Near IR laser (800nm) excitation causes a blue shift of the emission peak compared to 400 nm laser excitation. It is found that up-conversion luminescence is composed of a photoinduced trapping and a band edge excitonic state. The blue shift of the emission peak is caused by the relative change in luminescence intensity between excitonic and trapping states.
Keywords :
II-VI semiconductors; cadmium compounds; excitons; infrared spectra; photoluminescence; semiconductor quantum dots; spectral line shift; time resolved spectra; ultrasonic effects; ultraviolet spectra; visible spectra; CdSe-CdS; UV-visible absorption spectroscopy; band edge excitonic state; blue shift; core-shell quantum dots; luminescence intensity; near IR laser; photoinduced trapping; photoluminescence; steady-state luminescent property; time-resolved luminescent property; trapping state; ultrasonic irradiation; up-conversion luminescence; wavelength 400 nm to 800 nm; CdSe/CdS; Photoluminescence; Quantum dots; Up-conversion luminescence; core/shell;
Conference_Titel :
Communication Technology and Application (ICCTA 2011), IET International Conference on
Conference_Location :
Beijing
DOI :
10.1049/cp.2011.0821
