Synthesis and Optical Properties of Thiol Functionalized CdSe/ZnS (Core/Shell) Quantum Dots by Ligand Exchange

Table 2

Quantum yield of CdSe/ZnS core/shell QDs was increased with time and with more coating of ZnS layers in shell.

Samples	Area	FWHM	OD	QY
As-prepared CdSe QDs, no ZnS shell layer	49950.4	30.6	0.085 at 483 nm	0.7
1st ZnS monolayer	466234.0	32.9	0.094 at 485 nm	6.0
2nd ZnS monolayer	796708.1	31.9	0.097 at 485 nm	10.3
3rd ZnS monolayer	868612.7	30.6	0.097 at 485 nm	11.2
4th ZnS monolayer	975412.1	33.7	0.087 at 483 nm	13.5