Single-photon emission of CdSe quantum dots at temperatures up to 200 K

Abstract

We report on the generation of triggered single photons obtained from epitaxially grown self-assembled CdSe/Zn(S,Se) quantum dots for temperatures up to 200 K. At low temperatures (T<40 K) photon correlation experiments under pulsed excitation show nearly perfect single-photon emission from an individual CdSe quantum dot. For higher temperatures (T>40 K) an increasing multi-photon emission probability due to spectrally overlapping acoustic phonon sidebands of neighboring quantum dots is observed. We found that the multi-photon emission probability of a bare quantum dot (background subtracted) is strongly suppressed at 200 K if compared to a Poissonian light source of the same average intensity. Our results demonstrate the large potential of self-assembled CdSe/Zn(S,Se) quantum dots for nonclassical light generation at temperatures up to 200 K.