热分解含硫金属有机配合物制备近红外PbS量子点

Synthesis of near infrared PbS quantum dots by pyrolysis of organometallic sulfur complex

以Pb(NO3)2,Na(S2CNEt2)·3H2O为反应物,在去离子水中合成含硫金属有机配合物Pb(S2CNEt2)2.氩气保护下,在油酸和十八烯混合溶液中热分解前躯体Pb(S2CNEt2)2,反应时间分别为30,60,90,120 min,获得PbS量子点样品a,b,c,d.通过红外光谱分析和热重-差热等手段对前躯体进行表征,证明配体Na(S2CNEt2)·3H2O中的两个硫原子与Pb2+配位成功.PbS量子点样品X射线衍射和透射电子显微镜分析表明,合成的PbS为类球形纯立方晶系PbS纳米晶;对PbS量子点样品紫外-可见吸收光谱和光致发光谱进行研究发现,吸收光谱和光致发光谱随着反应时间的增加顺序红移,表明优化热分解反应时间可以调控PbS量子点的吸收光谱和光致发光谱.PbS量子点样品a发射峰在1080 nm,与硅基太阳能电池相匹配,可作为硅基荧光太阳能聚集器的荧光材料.

Sulfur metal-organic complex Pb（S2CNEt2）2 is synthesized with Pb（NO3）2 and Na（S2CNEt2）·3H2O as reactants in deionized water. Under the protection of argon, PbS quantum dots are synthesized by pyrolysis of the precursor Pb（S2CNEt2）2 in oleic and octadecene mixed solution. Four samples a, b, c, and d of PbS quantum dots are synthesized on the condition that the reaction times are 30, 60, 90, and120 min, respectively. Infrared spectrum of the precursor Pb（S2CNEt2）2 shows that two sulfur atoms of the ligand Na（S2CNEt2）·3H2O have successfully coordinated with Pb2＋. X-ray powder diffraction and transmission electron microscopy results show that the PbS nano crystals are of pure cubic phase structure, and are well-dispersed spherical particles. UV-visible absorption spectrum and photoluminescence spectra of PbS quantum dots show that absorption spectrum and photoluminescence spectra both have red-shift along with reaction time extending. This indicates that absorption spectrum and photoluminescence spectra can be modulated by optimizing the thermal decomposition reaction time. The emission peak of sample is located at 1080 nm, which is matched to the silicon solar cell. It can be used as the fluorescent material of silicon luminescent solar concentrator.