Photobleaching-resistant ternary quantum dots embedded in a polymer-coated silica matrix

Gugula, K.; Szydlo, A.; Stegemann, L.; Strassert, C. A.; Bredol, M.

Zusammenfassung

Herein we present the preparation of ultrastable CuInS2/ZnS-silica composites able to withstand high density irradiation for more than 100 h without degradation using a blue LED operated at 20 mA forward current. The high photostability is obtained by employing a novel polymer-infused silica/QD composite. The versatility of the (3-mercaptopropyl)trimethoxy-silane/tetraethyl orthosilicate matrix used in this study is demonstrated by incorporating QDs with positively (amine) and negatively (carboxyl) charged ligands yielding transparent and highly luminescent gels with up to 20% solid loading. Quantum yields in solution (40–50%) are retained or even slightly improved in the silica matrix further proving efficient encapsulation without damaging the nanocrystal surface. White LED fabricated from green and orange ternary QDs exhibit a luminous efficacy of 30 lm W−1 and a color rendering index of 87 as compared to a blackbody radiator with 3850 K color temperature.