Behind the Scenes At a Quantum Dot Factory

Tekla Perry writes: In a nondescript office complex in Milpitas, Calif., Nanosys is making enough quantum dots to populate 6 million 60-inch television screens annually. "The process goes on in what looks like a microbrewery. In about half a dozen large metal tanks ... Nanosys combines cadmium and selenium and adjusts the temperature, concentration, and catalysts added to force these precursors to combine into stable crystals of cadmium selenide. Then, by readjusting the conditions, the system stops the formation of crystals and triggers the beginning of crystal growth. A computer controls the process according to a programmed “recipe;” staff members monitor the growth of the crystals by shining light on them and measuring the wavelength of the fluorescence; the smallest crystals don’t fluoresce at all, then, as the crystals get larger, the wavelength changes. Nanosys stops the process when the fluoresced light hits the target wavelength, which varies depending on what particular display industry standard that the batch of film is designed to meet."