Herbages-derived fluorescent carbon dots and CdTe/carbon ensembles for patterning

We report a simple and effective route to easily prepare multi-emission carbon dots (CDs) and CdTe/carbon highly fluorescent assemblies by employing general and low-cost ubiquitous herbages as carbon source. Four kinds of herbages including radix pseudostellariae, ganoderma, liquorice, and angelica were pyrolyzed to straightly generate narrow-size distributed bare CDs. The as-prepared bare CDs have excellent solubility in various organic solvents without further treatment and exhibit bright photoluminescence with the quantum yields up to 28 %. After further treatment with nitric acid and amine-terminated compound 4,7,10-trioxa-1,13-tridecanediamine, the passivated CDs can be combined together with traditional CdTe QDs to form new ensembles for evoking their collective properties. The resulted CD solutions were proven that can be employed as fluorescent inks for patterning which may useful in anti-counterfeit and optoelectronic devices.