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

Table 3

Optical properties of thiol-linked CdSe/ZnS QDs before and after heat treatment at 60°C for 24 h under light with no inert gas protection.

Linkers	Molar ratio of CdSe/ZnS QDs to linkers	QY of QDs before heating (%)	QY of Qds after heating (%)
1,4-Benzenedimethanethiol (BMT)	4 : 1	23.4	17.1
	2 : 1	30.1	23.4
	1 : 2	26.9	28.1
	1 : 8	25.9	27.0
Biphenyl-4,4′-dithiol (BPDT)	4 : 1	20.0	18.8
	2 : 1	19.6	21.7
	1 : 2	19.4	25.1
	1 : 8	33.6	13.0
1,16-Hexadecanedithiol	4 : 1	30.2	22.7
	2 : 1	25.6	22.1
	1 : 2	27.7	29.1
	1 : 8	27.7	29.1
1,11-Undecanedithiol	4 : 1	23.5	20.1
	2 : 1	25.7	25.1
	1 : 2	25.9	25.9
	1 : 8	27.0	29.2
11-Mercapto-1-undecanol	4 : 1	21.3	18.5
	2 : 1	21.9	18.8
	1 : 2	23.4	21.2
	1 : 8	27.1	29.0
1,8-Octanedithiol (ODT)	4 : 1	22.9	20.8
	2 : 1	24.2	24.8
	1 : 2	25.5	27.5
	1 : 8	23.9	26.8
No linker	—	20.7	12.6