Synthesis And Electronic Transport Property Of CdS And ZnS Nanoarrays By SBA-15 Template Method

1D semiconductor nanoarrays which have the potential applications in the field of devices have attracted a great deal of attention due to its unique physical and chemical characteristics, such as light-emitting diodes (LEDs), flat panel displays, optical information storage and so on. Preparing highly ordered nanoarrays and investigating its unique characteristics are becoming an active field. In this thesis, highly ordered nanoarrays of CdS,ZnS were synthesized by SBA-15 template method and its Electronic transport properties were studied.In this thesis, the main work and the main results obtained are as following:1. Highly ordered mesoporous CdS, ZnS nanoarrays were synthesized by using SBA-15 hard template and cadmium xanthate (CdR₂) and Zinc xanthate (ZnR₂) as the single precursor. The nanoarrays were characterized by TEM,SEM,TG/DTA,XRD,N₂ adsorption/desorption,UV-VIS and PL. The results indicated that the nanowire arrays possessed highly ordered hexagonal mesostructure and fiber-like morphology, analogous to the mother template, and exhibited the Optics Properties.2. A single bundle of nanoarrays was assembled by AC electric field. Its electronic transport property was measured. The current-voltage characteristics of CdS nanoarrays are strongly nonlinear and asymmetrical, showing rectifying diode-like behavior. Nanoarrays make two the asymmetric contacts with the two Pt electrodes in the dielectrophoresis aligning process, and a back-to-back Schottky barriers structure is formed. Under UV illumination, the I-V characteristic of CdS nanoarrays could be greatly changed which showed that the nano-metal/semiconductors (nano-M/SCs) had photo-electric switching effect.In order to confirm the validity of the rectification for different metal sulfides prepared in this method, ZnS nanoarrays were prepared with the same template system. The experimental results illustrate that ZnS nanoarrays possess the rectifying diode-like behavior, the rectification ratio for ZnS nanoarrays is lower than the CdS nanoarrays.At the same time, we use the same method to synthesize the Cd_1-xZn_xS alloy, the results indicate that the nanowire arrays possesse highly ordered hexagonal mesostructure and fiber-like morphology, analogous to the mother template, and the XRD angles shift the lower angle, it shows that the parts of zinc have been doped into CdS.