Full‐Color Inorganic Carbon Dot Phosphors for White‐Light‐Emitting Diodes

Abstract

Light‐emitting carbon dots (CDots) are widely investigated due to their distinct merits. However, it is still a challenge to modulate their bandgap emissions and conquer their aggregation‐induced luminescence quenching to achieve full‐color highly emissive CDot‐based phosphors. Herein, this study proposes an approach toward realization of full‐color emissive CDots from two common precursors, citric acid and urea, through employing three different solvents (water, glycerol, and dimethylformamide) and their combinations in a solvothermal synthesis. Employing sodium silicate solution, this study further demonstrates the microwave‐assisted method allowing to incorporate CDots into a silica network, which effectively prevents aggregation of CDots and results in strongly luminescent full‐color inorganic CDot phosphors with photoluminescence quantum yields of 30–40%. Through deposition of the red‐ and green‐emitting CDot phosphors on blue‐emitting InGaN chips, white‐light‐emitting diodes are fabricated with Commission Internationale de L'Eclairage of (0.34, 0.31) and the color rendering index of 82.4, indicating their promising application for solid‐state lighting.