一种简单的水热法制备油溶性PbSe量子点

doi:10.15541/jim20140624

摘要/Abstract

摘要：

本研究采用简单的水热法得到了单一形态学和小尺寸分布的油溶性PbSe量子点。所得到的立方相PbSe量子点颗粒呈现近球形, 且平均颗粒尺寸为4.0 ± 0.5 nm。PbSe量子点在435 nm近紫外区域呈现出较强的和相对较窄的光致发光光谱, 光谱的半高宽值约为80 nm。随着反应时间的延长和反应温度的升高, 发光光谱向低能量区域移动, 谱峰的半高宽也随之变大。在改变前驱体Pb/S摩尔比的条件下, 发光光谱相对强度降低, 光谱也发生向长波长区域移动。另外, 随着反应温度和前驱体Pb/S摩尔比的改变, PbSe量子点颗粒表面的缺陷也增多。在反应过程中, 小颗粒长大成大尺寸颗粒促使PbSe量子点的发光光谱向长波长移动, 这个现象符合奥斯瓦尔德熟化定律。热力学不稳定和颗粒表面低浓度油酸包覆也造成PbSe量子点颗粒表面产生缺陷。

关键词: 水热法, PbSe量子点, 半导体, 光致发光光谱

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

中图分类号:

TQ110

杨丰桕, 陆梦晨, 张欣, 张延, 王连军, 江莞. 一种简单的水热法制备油溶性PbSe量子点[J]. 无机材料学报, 2015, 30(7): 774-778.

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.

图/表 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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