Quenching-resistant carbon nanodots with enhanced luminescence by tailoring functional groups

Abstract

Enhancing the luminescence efficiency and stability of solid-state phosphor with facile processability is essential for various applications. Carbon-based materials might have proper optical properties and durability under ambient condition. However, the carbon-based phosphors usually showed severe quenching of the photoluminescence in the absence of solvent. Alkylamine-functionalization of the carbon-based phosphors can alleviate the quenching, but it resulted in low luminous efficiency. In this study, tailoring the functional groups of carbon nanodots (CNDs) was carefully studied through alkylamine-functionalization and reduction. The reduction with $NaBH_4$ changed the electron-withdrawing functional groups on the alkylamine-functionalized CNDs to the electron-donating groups, enhancing the luminescence efficiency and quenching-resistance. The delicate modulation in alkylamine-functionalization and reduction enabled efficient and robust photoluminescence in the film without any host materials.