论文部分内容阅读
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Pb Se量子点。所得到的立方相Pb Se量子点颗粒呈现近球形,且平均颗粒尺寸为4.0±0.5 nm。Pb Se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,Pb Se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Pb Se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Pb Se量子点颗粒表面产生缺陷。
In this study, a single morphological and small size distribution of oil-soluble PbSe quantum dots was obtained by a simple hydrothermal method. The resulting PbSe QDs have a nearly spherical shape with an average particle size of 4.0 ± 0.5 nm. The PbSe QDs exhibited strong and relatively narrow photoluminescence spectra in the near-UV region of 435 nm with a FWHM of about 80 nm. With the extension of the reaction time and the increase of the reaction temperature, the luminescence spectrum moves to the low energy region, and the full width at half maximum of the spectrum peak also increases. Under the condition of changing the molar ratio of Pb / S precursor, the relative intensity of the emission spectrum decreases and the spectrum also moves to the long wavelength region. In addition, as the reaction temperature and the precursor Pb / S molar ratio change, PbSe quantum dot particle surface defects also increased. During the reaction, small particles grow into large size particles to promote the emission spectrum of Pb Se quantum dots to move to a longer wavelength. This phenomenon accords with Oswald ripening law. Thermodynamically unstable and low concentration oleic acid coating on the surface of the particles also causes defects on the surface of Pb Se quantum dot particles.