Formation of High Efficiency InP-Based Nanocrystal Films Using Acrylate Polymers
Gearhart, Steven M.
MetadataShow full item record
Lighting accounts for a significant amount of energy use in modern society and consequently, improving lighting efficiency has been a long standing goal towards energy conservation. Replacing the natural but very inefficient light of incandescent bulbs with fluorescence bulbs has helped increased efficiency but has lowered the quality of white light emitted. Fluorescent bulbs are also partially toxic which has lead researchers to investigate the potential of LEDs. LEDs hold potential for a high natural light quality along with high efficiency. Commercial white LED bulbs are on par with commercially available compact fluorescent bulbs. To make white light LEDs more efficient, researchers have looked to replace bulk phosphors that are used to partially convert the blue LED light to green and red light (to form white light). Nanocrystals have the ability to emit in narrow spectrums, so that, for example, the red phosphor light is not emitted in the far-red or infra-red portion of the spectrum where the eye response is poor or zero. However, nanocrystals are not as easily handled as bulk phosphors and readily oxidize if exposed to air or water; thus, a protective coating is typically needed. The work in this thesis demonstrates that it is possible to make a highly efficient (75%-80%) InP-based nanocrystal film in Poly(lauryl methacrylate) (PLMA). The film not only has high efficiency at room temperature, but it has high good efficiency at high temperatures. The nanocrystals exhibit a negligible loss in efficiency when transferred into the polymer, a loss of ~10% at high temperatures (which returns to normal when cooled), and are non-toxic.