Facile Hydrothermal Synthesis of Oil-Soluble PbSe Quantum Dots

doi:10.15541/jim20140624

Abstract

Abstract:

Oil-soluble PbSe quantum dots (QDs) with uniform morphology and narrow size distribution were obtained via a facile hydrothermal approach. The cubic PbSe QDs with nearly spherical shape and average diameter of (4.0 ± 0.5) nm were obtained. The as-synthesized PbSe QDs showed a strong and a relatively narrow band edge emission in the near purple region at 435 nm and a small full width at half maximum (FWHM) approximately of 80 nm. The photoluminescence (PL) spectra moved to low energy region and FWHM became broad when the reaction time extended and the synthesis temperature increased. The PL spectra exhibited less intense and well defined features at long wavelength which were ascribed to low energy transitions as varying Pb/S molar ratios. In addition, the defect luminescence of PbSe QDs became more obvious with the synthesis temperatures and Pb/S molar ratios increasing. The PL spectra of PbSe QDs shifted to long wavelength (low energy region), because small particles coalesced into form large particles during reaction, which was in agreement with the Ostwald ripening principle. The defects of PbSe QDs may result from thermodynamically instable and lower densities of capped oleic acid.

Key words: hydrothermal approach, PbSe quantum dots, semiconductor, photoluminescence

CLC Number:

TQ110

YANG Feng-Jiu, LU Meng-Chen, ZHANG Xin, ZHANG Yan, WANG Lian-Jun, JIANG Wan. Facile Hydrothermal Synthesis of Oil-Soluble PbSe Quantum Dots[J]. Journal of Inorganic Materials, 2015, 30(7): 774-778.

Figures/Tables 4

Fig. 1 TEM images of the as-synthesized PbSe QDs (a) TEM image; (b) HRTEM image; (c) Histogram of crystal size distribution

Fig. 2 XRD pattern of the as-synthesized PbSe QDs

Fig. 3 PL spectra of the as-synthesized PbSe QDs synthesized at 423 K (Pb/Se = 1: 1.2) (a) Selenourea selected as selenium source; (b) Selenium dioxide selected as selenium source

Fig. 4 PL and absorption spectra of the as-synthesized PbSe QDs synthesized at 423 K for 1 h (Pb/Se = 1: 1.2) (a), PL spectra of the as-synthesized PbSe QDs with different reaction temperatures (b) and molar ratios of Pb/Se (c)

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