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Quantum Dot LED for Efficient White Light Source

The finding at Vanderbilt University has got many publicity this week, in the wake of global high energy price. The technique is based on a certain specie of quantum dot called magic-sized quantum dots. What this means is the dot size is naturally preferred, and thus easy and fast to grow. (In the case of Cadmium Selenide, it is 33-34 atoms in a dot.)

 

Taking in radiation from a blue LED, these quantum dots emit light in the 420-710 nm range, which cover a large portion of the visible spectrum. (Source other than blue LED will not change the output spectrum, a nice feature)

 

More importantly, the energy distribution is not too different from sunlight, which means it better suits our eyes compared to fluorescence. The fact that it doesn’t emit infrared means the ‘bulb’ can be cool when operated, and we get more visibility per energy unit. (read: cheaper lighting)