| In the era background that the information technology is rapidly developing, traditional inorganic and organic semiconductor materials exhibit some performance bottlenecks. The processing technology of inorganic semiconductor materials is relatively complex, and has difficulty in large area processing. Flexible material cannot be prepared by inorganic materials. Although the processing technology of organic materials is not restricted as inorganic materials, the low carrier concentration and mobility are greatly limited the application scope. Carrier mobility is one of the most important parameters which decides the performance of semiconductor device. It is significantly related to the work frequency of the device, signal to noise ratio, power density, the photoelectric conversion efficiency, etc. At the same time, for a semiconductor device, such as solar cells and gas sensor, the poor ability of electric carrier transport can cause the material internal charge can't delivery in a timely and effective manner to the external circuit, which affect the device performance.Facing all these difficulties, the ideal solution is to prepare organic and inorganic composite materials which could balance the advantages of organic materials and inorganic materials, including the high carrier mobility of inorganic materials and processing facility of organic materials. The starting point of this idea is to study how to prepare organic and inorganic composite semiconductor materials with excellent electrical performances. Our studies are carried out based on inorganic material SnO2 and organic material P3HT. The research routine is designed as follows:First, porous SnO2 nano solid with ideal porosity, specific surface area, carrier mobility and other parameters is prepared by SnO2 nanoparticles through a certain process. Then, compose P3HT and porous SnO2 nano solid through proper process in order to prepare the P3HT-SnO2 organic and inorganic composite semiconductor with high carrier concentration and mobility. Our work is divided into six chapter in this thesis. The logical arrangement is described as below:Chapter 1:Introduction. Firstly, the background of this study, domestic and foreign development status of organic and inorganic composite materials were introduced. On this basis, we put forward our research content and the key scientific issues that we are willing to solve. The organic and inorganic materials are selected to be P3HT and SnO2 nanoparticle, respectively. To carry out the study of the material selection, the organic and inorganic materials we selected are P3HT and SnO2 nanoparticles. In this chapter, we talk about our material selection criterion and the basic physical and chemical properties of the material we selected.Chapter 2:Preparation of porous SnO2 nano solid and its mobility improvement study. SnO2 nanoparticle is one of the initial materials in our study. In the process of preparing the composite semiconductor, the first step is to prepare porous SnO2 nano solid by SnO2 nanoparticles. Due to the performance of composite semiconductor materials are significantly related to the performance of SnO2 porous nano solid, the selection of preparation devices and the design of processing method are of particularly importance. In this chapter, the preparation devices and the processing methods are described in detail, and a series of detailed analysis of the key parameters in the process of preparation of porous SnO2 nanosolids which influence the performances of prepared materials is talked about. The aspects that we analyzed include creation of pore forming agent dosage, hot pressing temperature, pressing pressure, calcination temperature and calcination atmosphere. Finally, through the comparative experiment, the best preparation method is determined.Chapter 3:The search of the improvement of P3HT film mobility and test method. Organic material P3HT is another initial material in our study. Therefore, "the best state" for P3HT is required in the preparation process of composite materials. P3HT is covered on the surface of porous SnO2 nano solid channels and possesses a form of thin film. In this chapter we focus on the method of how to improve the mobility of P3HT thin film. In our study, the traditional TOF method for film mobility test was improved. AC (alternating current) is added to DC (direct current) component in order to stabilize the TOF signal.Chapter 4:The invasive research for P3HT and SnO2 porous nano solid. Essentially, composite process is the infiltration process between different materials. Therefore, the research of the infiltration between P3HT and porous SnO2 nano solid is of extreme importance to the preparation of composite materials. In this chapter, we investigate the change of contact angle of two materials in different conditions and the contact angle measurement devices are established by ourselves. The contact angle can provide significant references of the synthesis routines of the composite materials.Chapter 5:The mobility improvement of the P3HT-SnO2 composite semiconductor. Based on the study of the previous chapters, in this chapter the P3HT-SnO2 composite semiconductor is prepared and its electrical performance improvement is discussed. By using Raman spectra and XPS spectra, we prove that chemical bond is formed and electron transfer is realized between P3HT and SnO2 under this synthetic technology. Hall Effect measurements indicate that the carrier concentration and mobility of the composite semiconductor are increased by 29 and 37 times. At the same time, we theoretically explain the composite effect from the aspect of energy band. Because the conduction band (CB) of SnO2 is very close to the highest occupied molecular orbital (HOMO) of P3HT, the electron transfer between the two materials is facilitated through proper composite technology. At last, we discuss the effects of different composite conditions on the properties of composite semiconductor materials.Chapter 6:Summarization and prospect. In this chapter, we summarize our work and point out our main conclusions and innovations of our research. At the same time, the future work is prospected. |
PDF Full Text Request