Efficient carbon dot-based fluorescence-afterglow dual-mode white-light materials via surface modification

Abstract

White afterglow materials have attracted considerable attention owing to their promising applications in illumination displays, biological imaging and information encryption. However, research on high-efficiency photoluminescence (PL) and afterglow dual-mode white emission remains rare. Here, we report a simple strategy to fabricate carbon dots (CDs)-based PL and afterglow dual-mode white emission materials, in which (3-aminopropyl) trimethoxysilane (APTMS) and rhodamine 6G (Rh6G) are combined as precursors through a hydrothermal reaction. After the subsequent modification with urea, dual-mode white emission CDs (Si-CDs@u) exhibiting Commission Internationale de l’Eclairage (CIE) coordinates of (0.38, 0.41) for PL and (0.40, 0.43) for afterglow were successfully synthesized, achieving a high PL quantum yield (QY) of 65 ± 1%. Experimental analysis confirms that the short-wavelength emission originates from room temperature phosphorescence (RTP) of APTMS-derived CDs, whereas the long-wavelength emission arises from delayed fluorescence via energy transfer between the RTP-active CDs and subluminophores on their surface. Finally, we presented the application of Si-CDs@u in the white-light emitting diode and afterglow display fields.