Performance Tuning Of PbS Colloidal Quantum Dots By Solution Processing

The development of low-dimension structures and physics change the design ideas ofelectronic devices. Now "energy band engineering" becomes the new technology forsemiconductor devices. Semiconductor quantum dots are the most typical application inthe field of semiconductor materials. We can control the shape, structure and size ofquantum dots in order to optimize the bandgap, exciton binding energy and exhibit blueshift. It helps to produce large-area quantum dots devices for a variety of applications.In this paper, technical development of solar cell and the concept of semiconductorquantum dots are presented first, and we introduce the low-dimension physical properties,development status and applications of semiconductor quantum dots. Then we point outsome approaches on preparation of quantum dots and analyze the mechanics of quantumdots growth in details. Here we report on the synthesis of semiconductor PbS colloidalquantum dots with good size distribution through a facile and rapid approach using in situgenerated H2S as sulfur source and Pb(Ac)23H2O acts as lead source with interaction ofoleic acid, diphenyl ethers,1-octadecene and dodecylamine, and in this project, we stillstudy the process of fabricate PbS quantum dots thin films as utilized spin coating. Ingeneral, spin coating20-30times can achieve good performance thin films and theconcentration of PbS quantum dots is50-100mg/ml.We analyzed the optical properties of quantum dots by UV-Vis spectrophotometer(UV), Fourier transform infrared spectrophotometer (FTIR) and photoluminescencespectra (PL). The morphology, crystalline form is characterized by transmission electronmicroscopy (TEM) and X-ray diffraction (XRD). According to the differentcharacterization results we continue to design a series of experiments to explore theoptimum reaction condition, and finally we synthesis PbS colloidal quantum dots that aremonodispersed.