Jun
10
A Silicon Quantum Dot White Blue LED Made
June 10, 2015 | Leave a Comment
Hiroshima University researchers have announced fabrication of a silicon quantum dot based hybrid inorganic/organic light-emitting diode (LED) that exhibits white-blue electroluminescence. The hybrid LED is expected to be a next-generation illumination device for producing flexible lighting and displays.
The fabrication was done by Professor Ken-ichi Saitow at the Natural Science Center for Basic Research and Development, Hiroshima University and graduate student Yunzi Xin, Graduate School of Science, Hiroshima University, and their collaborators.
Semiconductor quantum dots (QDs) can produce full-color luminescence through tuning of the particle size. QDs have attracted significant attention as potential components of next-generation solid-state light sources, including LEDs.
The Si QD hybrid LED was developed using a simple method; almost all processes were solution-based and conducted at ambient temperature and pressure. Conductive polymer solutions and a colloidal Si QD solution were deposited on the glass substrate. The current and optical power densities of the LED are, respectively, 280 and 350 times greater than those reported previously for such a device at the same voltage (6v). In addition, the active area of the LED is 4 mm2, which is 40 times larger than that of a typical commercial LED; the thickness of the LED is 0.5 mm.
Professor Saitow said, “QD LED has attracted significant attention as a next-generation LED. Although several breakthroughs will be required for achieving implementation, a QD-based hybrid LED allows us to give so fruitful feature that we cannot imagine.”
Quantum dot LEDs have been of great interest for some time due to their relative simplicity and considerable theoretical light output. This research takes the research from some odd color examples into the white realm, the color inclusive of all colors of visible light. That fact and the huge jump in overall output increased hundreds of times is cause for acclaim.
Even more impressive is the apparent simplicity and low threshold of conditions in the fabrication. Who would have thought a year ago that quantum dot LEDs might be made from solutions at room temperature and pressure?
Today’s LEDs are very impressive, indeed. This research result shows the LED future to be just getting opened up.