单体摩尔比对PbSe纳米粒子生长的影响

Influence of Monomer Molar Ratio on the Growth of PbSe Nanoparticles

研究了不同温度下,硒单体与铅单体的不同摩尔比对PbSe纳米粒子晶体成核和晶体生长的影响.实验结果表明,当硒与铅的摩尔比较大时,PbSe纳米粒子在晶体成核阶段成核比较容易,但在晶体生长阶段的生长比较缓慢.一方面原因在于硒单体的活度较大,当单体摩尔比较大时,溶液超饱和度增大,晶体成核相对容易,同时会消耗过多的单体.当PbSe纳米粒子进入晶体生长阶段时,硒与铅的单体浓度减小,影响到PbSe纳米粒子的生长速度.另一方面原因在于PbSe纳米粒子的外壳是铅壳的纳米晶结构.

In order to study the influence of selenium to lead monomer molar ratio on the growth of PbSe nanoparticles,PbSe nanoparticles with different molar ratio of selenium to lead monomer were synthesized.Experimental results indicate that the more selenium monomers＇ existed in the initial stage,the faster the nucleation process occurred,but slow the growth of nanoparticles.One reason is that selenium monomer is more active than the lead monomer.The more selenium monomers exist in the initial stage,the degree of supersaturation is higher,and therefore the faster nucleation process occurred.As a result,the remaining monomer concentration in the solution decreases significantly right after the nucleation stage,the degree of supersaturation is lower at the time,which results that growth of PbSe nanoparticles slows.The other reason is the special PbSe nanoparticle crystal structure.