Photostability of single-photon emission from a single quantum dot in the 650-nm wavelength band at room temperature

The photoluminescence correlation from a single CdSe nanocrystal under pulsed excitation is studied, and a single photon is realized at wavelength 655 nm at room temperature. The single colloidal CdSe quantum dot is prepared on a SiO2/silicon surface by a drop-and-drag technique. The long-term stability of the single-photon source is investigated; it is found that the antibunching effect weakens with excitation time, and the reason for the weakening is attributed to photobleaching. The lifetimes of photoluminescence from a single quantum dot are analyzed at different excitation times. By analyzing the probability distribution of on and off times of photoluminescence, the Auger assisted tunneling and Auger assisted photobleaching models are applied to explain the antibunching phenomenon.

National Nature Science Foundation of China 60537010 60877030National Basic Research Program of China 2009CB320300 Scientific Research 20510112 The authors acknowledge the support from the National Nature Science Foundation of China (Grants No. 60537010, 60877030), National Basic Research Program of China (2009CB320300) and Grant-in-Aid for Scientific Research (C) (20510112).