Sponsors / Partners

Accenture Microsoft NYSE Shell Salesforce AAAS Science Red Herring Fortune CNN Time Magazine
 

2004 World Technology Awards Winners & Finalists

Quantum Dot Corp.

Please describe the work that you are doing that you consider to be the most innovative and of the greatest likely long-term significance.

Founded in 1998, Quantum Dot Corporation (QDC) develops and markets novel solutions for biomolecular detection. QDC's products and services employ quantum dot (Qdot®) particles, tiny semiconductor crystals that emit light brightly in a range of sharp colors.  These nanometer-sized Qdot particles have unique, highly desirable properties that make them a superior detection platform for biology.  QDC has invested many years in perfecting the methods for synthesis of high quality, high brightness quantum dots for biology. 

The use of colloidally dispersed pigments is so old that it is essentially a history of humankind's pursuit of color. Stone Age peoples made use of such pigments in paintings dating from the dawn of civilization itself. Ancient Egyptians prepared colloidal dispersions as inks. Though not understood as such, these technologies were already widespread by the Middle Ages. Such understanding wouldn't come until the 1850s and 1860s when visionaries such as Michael Faraday began to unravel the reasons behind the extraordinary properties of nanocrystalline systems. (Evans, D. F. and Wennerström, H. "The Colloidal Domain Where Physics, Chemistry, and Biology Meet," 2nd ed., Wiley-VCH: New York, 1999).

The illuminated geometries of 19th Century stained glass windows are a fitting harbinger to Quantum Dot Corporation's brilliantly luminescent Qdot® nanocrystals. Victorian era glass-melt recipes for red and orange colors contain, essentially, dilute concentrations of nanocrystallites (from zinc and cadmium sulfides and selenides). However, the richly hued progenitors lacked the fluorescence of the quantum dots currently developed at Quantum Dot Corporation (QDC).

Modern quantum dot technology traces its origins, in part, to the mid-1970s quest for new answers to meet the worldwide energy crisis. Research in photo-electrochemistry (e.g., solar energy conversion) was tapping the semiconductor/liquid interface to exploit the advantageous surface area-to-volume ratio of nanocrystal particles for energy generation. Seminal developments arose in the early 1980s from two labs, worlds apart: Dr. Louis Brus at Bell Laboratories, and Drs. Alexander Efros and A.I. Ekimov of the Yoffe Institute in St. Petersburg (then Leningrad) in the former Soviet Union. Dr. Brus and his collaborators experimented with nanocrystal semiconductor materials and observed solutions of strikingly different colors made from the same substance. This work contributed to the understanding of the quantum confinement effect that explains the correlation between size and color for these nanocrystals. Bell Labs scientists were studying the optical phenomena that occur when the properties of bulk semiconductor materials change. This transition happens when the structures themselves become smaller than a fundamental scale intrinsic to the substance. In nanocrystals' size regime, the Bohr radius of the electron-hole pair determines the scale length.

Two of these Bell Labs scientists - Dr. Moungi Bawendi and Dr. Paul Alivisatos - moved to MIT and UC Berkeley, respectively, and continued investigating quantum dot optical properties. These researchers found ways to make the quantum dots water-soluble. They also discovered that adding a passivating inorganic "shell" around the nanocrystals, and then shining blue light on them, caused the quantum dots to light up brightly. Quantum Dot Corporation is the exclusive licensee of several of their discoveries. As the images of stained glass windows radiated in past centuries, Quantum Dot Corporation illuminates the path to scientific discovery in our new millennium.