SAIT Develops the World’s First Full-color Quantum Dot Display

Quantum dots are semiconductor crystals measured in nanometers (nm=one-billionth of a meter) that change colors depending on their sizes. They have emerged as the next-generation optic materials because their luminous wavelengths can be easily controlled and have high quantum efficiency and outstanding optic stability. However, a display using quantum dots were perceived to be limited due to difficulty in scaling up.

In the recent study, noting that difficulty in producing a quantum dot display is due to conventional patterning methods such as photolithography or inkjet, SAIT adopted a new patterning method referred to as transfer printing and enabled in developing a large-scale quantum dot display.

SAIT achieved a breakthrough in patterning by creating red, green and blue quantum dot films, which are necessary to produce a display, on separate wafers and pressing a stamp to wafers where quantum dots are printed to pick up and transfer them to the substrates. The adoption of this method enabled large-scale quantum dot displays to be produced and moreover, luminous efficiency was improved as quantum dots can be rearranged tightly in a process of transferring quantum dots to the substrates. Through this method, SAIT succeeded in realizing quantum dot displays not only on glass but also on plastic substrates and confirmed the possibility of producing flexible quantum dot displays in the future.

Jong-min Kim, an SAIT fellow who led the research, said, “The development of the new patterning method using transfer printing is significant as it paved the way for developing a large-scale display using quantum dots. It will become the key base technology in QD displays, QD LEDs, and QD photovoltaics in the future.”