The global demand for resource sustainability is growing. Thus, the development of single-source, environment-friendly colloidal semiconductor nanocrystal （NC） phosphors with broadband emission spectra is highly des...The global demand for resource sustainability is growing. Thus, the development of single-source, environment-friendly colloidal semiconductor nanocrystal （NC） phosphors with broadband emission spectra is highly desirable for use as color converters in white light-emitting diodes （WLEDs）. We report herein the gram-scale synthesis of single-source, cadmium-free, dual-emissive Mn-doped Zn-Cu-In-S NCs （d-dots） by a simple, non-injection, low-cost, one-pot approach. This synthesis method led to the formation of NCs with continuously varying compositions in a radial direction because each precursor had a different reactivity. Consequently, the d-dots exhibited two emission bands, one that could be attributed to Mn emission and a second that could be ascribed to the band edge of the Zn-Cu-In-S NCs. The emission peaks assigned to band edge were tunable by modifying the particle size and composition. The prepared d-dots also exhibited the characteristic zero self-absorption, a quantum yield of 46%, and good thermal stability. Combining a commercial blue light-emitting diode （LED） chip with optimized d-dots as color converters gave a high color rendering index of up to 90, Commission Internationale de l＇eclairage color coordinates of （0.332, 0.321）, and a correlated color temperature of 5,680 K. These results suggest that cadmium-free, thermally stable, single-phase d-dot phosphors have potential applications in WLEDs.展开更多
基金This work was supported by the National Natural Science Foundation of China （Nos. 21373097 and 51072067） and the National Basic Research Program of China （No. 2011CB935800）.
文摘The global demand for resource sustainability is growing. Thus, the development of single-source, environment-friendly colloidal semiconductor nanocrystal （NC） phosphors with broadband emission spectra is highly desirable for use as color converters in white light-emitting diodes （WLEDs）. We report herein the gram-scale synthesis of single-source, cadmium-free, dual-emissive Mn-doped Zn-Cu-In-S NCs （d-dots） by a simple, non-injection, low-cost, one-pot approach. This synthesis method led to the formation of NCs with continuously varying compositions in a radial direction because each precursor had a different reactivity. Consequently, the d-dots exhibited two emission bands, one that could be attributed to Mn emission and a second that could be ascribed to the band edge of the Zn-Cu-In-S NCs. The emission peaks assigned to band edge were tunable by modifying the particle size and composition. The prepared d-dots also exhibited the characteristic zero self-absorption, a quantum yield of 46%, and good thermal stability. Combining a commercial blue light-emitting diode （LED） chip with optimized d-dots as color converters gave a high color rendering index of up to 90, Commission Internationale de l＇eclairage color coordinates of （0.332, 0.321）, and a correlated color temperature of 5,680 K. These results suggest that cadmium-free, thermally stable, single-phase d-dot phosphors have potential applications in WLEDs.
