Fluorescent nanocrystals are currently being applied in lasers or displays, and offer exciting prospects for future photonics such as quantum emitters. The nanocrystal shape plays an important role in these applications. Flat CdTe quantum disks with high fluorescence efficiency therefore provide an interesting possibility to explore the shape- and crystal structure-dependent fluorescence properties of semiconductor nanocrystals. We synthesized these CdTe semiconductor quantum disks from disk-shaped Cu2Te nanocrystals via cation exchange, and measured their photoluminescence (PL) spectral properties, quantum efficiencies and lifetimes.
The disks show a PL peak that can be tuned continuously from 600 to 640 nm according to their thickness. We also reached a faster PL decay time compared to spherical CdTe quantum dots, which confirms that simply tuning the shape can strongly improve conditions for lasing or single-photon emission. In addition, the current synthesis also leads to more stable nanocrystals compared to conventional preparation methods, opening up the way for practical application of the quantum dots. We measured the PL using the FLS920 photoluminescence spectrometer from Edinburgh Photonics (www.edinburghphotonics.com). The results were recently published in the Journal of the American Chemical Society (http://dx.doi.org/10.1021/ja404694k).
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