Emission enhancement of a carbazole-based fluorophore on a quantum dot surface.

A novel carbazole-based fluorophore 5-(carbazol-9-yl)-5'-mercapto-2,2'-bithiophene (CBTSH) was synthesized. CBTSH exhibited emission enhancement when attached to the surface of CdSe quantum dots (QDs). The emission quantum yield of CBTSH attached to CdSe is almost 5 times larger than that of CBTSH alone. The emission enhancement of CBTSH on the CdSe surface is due to the restriction on the rotational and vibrational motions of the carbazolylbithienyl unit as a result of QD aggregation.