Design And Fabrication Of High Photoluminescent Quantum Yield Carbon Nanodots Freestanding Composite Film

Carbon nanodots(C-dots)have attracted great attention for their biocompatibility and strong tunable photoluminescence(PL).However,aggregation-induced PL quenching blocks their practical application in solid-state optoelectronics.Here,we report a luminescent C-dots freestanding film with a substantially enhanced high quantum yield(QY)of 72.3%.A facile template method,rather than complicate lithography and etching technique is proposed to fabricate the C-dots composite films with large-area(8 inch × 8 inch)ordered patterns on the surface,such as micro-scale inverted-pyramid structure,nano-scale inverted-pyramid structure,and micro-scale spheres.The control experiment,FDTD optical simulation and theoretical analysis demonstrate the key success to QY enhancement lies in the separation of C-dots and the pattern of different micro-scale or nano-scale structures.This work realizes the QY enhancement simply by geometrical optics,not the chemical treatment of luminescent particles.It provides a general approach to fabricate large-area freestanding luminescent composite film with high QY.