Low‐Cost Water Soluble Silicon Quantum Dots and Biocompatible Fluorescent Composite Films

Abstract Silicon quantum dots (Si‐QDs) with the advantages of excellent biocompatibility, rich sources of raw materials, and low synthesis cost, are attracting enormous attention as ideal candidates for replacing existing semiconductor quantum dot products. The water‐soluble fluorescent Si‐QDs and the Si‐QDs/Chitosan composite material are successfully prepared here by combined microwave‐assisted and traditional one‐step hydrothermal synthesis using sodium citrate and 3‐(2‐aminoethylamino) propyl‐dimethoxymethylsilane (CG602) as a novel precursor. Experimental results show that the photoluminescence quantum yield of the prepared Si‐QDs is higher than 85%, and the particle size is uniform with low crystallinity. Chitosan is used as a film‐forming substance, while an appropriate amount of nontoxic glycerin is added as a plasticizer, and a certain amount of Si‐QDs are added to prepare a composite fluorescent film. The film is a composite material with excellent properties such as visible light transmittance greater than 80%, elongation at break greater than 25%, and excellent tensile strength.