Synthesis of Effective and Qualified Cu-doped ZnSe Quantum Dots and Their Optical Properties

doi:10.3724/SP.J.1077.2013.12184

Abstract

Abstract:

Effective Cu-doped ZnSe quantum dots (ZnSe:Cu d-dots) with high qualities were synthesized by a growth-doping strategy. The effect of the ratios of Zn to Se precursor within the raw materials on the quality of the ZnSe cores and ZnSe:Cu d-dots was studied. The photoluminescence (PL) properties of ZnSe:Cu d-dots in Cu doping process were investigated systematically. The results suggested that the optical performance and stability of the d-dots could be remarkably improved by further coated with a homogeneous ZnSe shell on the fabricated surface-doped ZnSe:Cu d-dots. In addition, the obtained ZnSe:Cu d-dots could be changed to be water-soluble by ligand exchange. It implied that these novel d-dots could be a promising candidate to substitute for the conventional quantum dots containing Cd elements, suggesting their potentially environment-friendly applications in the fields of solid state lighting and diagnostics.

Key words: ZnSe, quantum dots, growth-doping strategy, photoluminescence

CLC Number:

TM23

ZHENG Jin-Ju, CAO Sheng, GAO Feng-Mei, WEI Guo-Dong, JIA Long, YANG Wei-You. Synthesis of Effective and Qualified Cu-doped ZnSe Quantum Dots and Their Optical Properties[J]. Journal of Inorganic Materials, 2013, 28(2): 159-164.

Figures/Tables 5

Fig. 1 Temporal evolution of UV-Visible spectra of ZnSe QDs with n(Zn):n(Se)=1:15 (a), UV-Visible (left in (b)) and PL (b) of ZnSe QDs with various precursor ratios from 1:15 to 1:5, in which the QDs were taken from the three-neck flask at 5 min after the Se precursor injected

Table 1 Temporal evolution of the peak positions in UV-Visible spectra of ZnSe QDs with different n(Zn):n(Se)

n(Zn):n(Se)	0.5 min	2 min	5 min	10 min	20 min
1:5	378	388	391	390	388
1:10	375	384	385	386	388
1:15	370	386	386	388	387

Fig. 2 UV-visible (a) and PL (b) spectra of ZnSe core, ZnSe:Cu 40 min, ZnSe:Cu 80 min, ZnSe:Cu/ZnSe-1, ZnSe:Cu/ZnSe-2, ZnSe:Cu/ZnSe-3, and the PL spectra (c) of ZnSe:Cu 80 min excited at 320 nm, 335 nm and 350 nm, respectively

Fig. 3 Typical XRD pattern of as-synthesized ZnSe:Cu/ZnSe-3 QDs. The inset is a representative TEM image of this sample

Fig. 4 PL spectra and corresponding PL QY of ZnSe:Cu QDs before and after thiol ligand exchange

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