硫化铅量子点的能带调控

摘要：纳米材料的研究在近年来是材料科学中研究的重点方向，而纳米硫化铅作为新型的具有特殊光学性能的材料在各个领域都受到广泛应用。我们通过实验以求控制其量子点的颗粒变化，从而进一步研究其本身性质的改变。文中我们采用化学液相法，使用溶液混合反应共沉淀制备硫化铅量子点，并通过X射线衍射（XRD）、透射电子显微镜（TEM）和紫外可见分光光度计（UV-vis）进行表征分析。实验过程中我们成功的通过调制反应溶液的浓度和添加表面活性剂的方法改变了硫化铅量子点的颗粒尺寸，制备了粒径由7nm到20nm的硫化铅量子点。颗粒尺寸的变化也导致了量子点光学特性和能带的改变。从实验的结果上可看出，实验成功制备了结晶性良好的纯硫化铅量子点，再通过形貌及性能的表征分析后，发现量子点的能带岁颗粒尺寸大小变化的规律。通过对量子点本身光学性能的研究，我们可以使其在太阳能电池等领域获得更好的应用，同时对新型材料的发展起到促进作用。关键词：硫化铅；量子点；能带；调控

Modulation of the Band Gap of Lead Sulfide Quantum Dots

Abstract:Nanomaterials have been concerned many attentions, researchers use Lead sulfide quantum dots in all sorts of fields due to the special optical property. In our study, in order to explore the performance of the Lead sulfide quantum dots, we adopted chemical process to control the size of the sample. Lead sulfide quantum dots were prepared by Liquid phase method and morphology features of the sample was tested by XRD and TEM, the optical property was tested by UV-vis. The size of the particles is changed under the condition of controlling the concentration of the reaction solution and the addition of the surfactant and the particle size of the nanoparticles varies between 7 and 20 nm, which results in the change of the optical properties and the band gap of the particles. The optical band gap of lead sulfide QDs increases drastically with the decrease of the diameter of the sample QDs. Due to the test result, the sample with high crystallinity was successfully prepared by chemical process, and the test result shows the rule of quantum dot size change. By the research of the optical property, Lead sulfide quantum dots can get a better achievement in the solar cell and enhance the improvement of the novel materials. Key words: Lead sulfide; quantum dots; Band gap; Modulation