Study On Silicon Nanowires Array's Spectral And Electrical Characteristics

In recent year, the preparation, characteristics and application of the micro/nano-materials, especially the nanostructural semiconductors based on silicon, have attracted more and more attention in many fields.The wet etching method is one of the optimal technologies to fabricate the silicon nanowires(SiNWs) due to simple equipment, low price, high efficiency and good repeatability. The average size is approximately 70nm for the as-grown SiNWs fabricated by the wet etching method. The investigation of spectral and electrical characteristics based on this kind of SiNWs provides scientific basis for the application in the energy source and photoelectric devices. The mainly works are listed as following.First, The diffirent characterization techniques and related theory of the SiNWs' spectral and electrical characteristics had been analyzed.Second, The structural characterization was investigated by X-ray diffraction(XRD), scanning electron microscope(SEM), transmission electron microscope(TEM) and high resolution transmission electron microscopy(HRTEM). The optical property of the SiNWs was investigated by Fourier Transform Infrared Spectroscopy(FTIR), Raman scattering spectrum and photoluminescence(PL).Third, The structure of PtSi/p-SiNWs/p-Si /Al Schottky barrier diode was fabicated succeedly. The effect of different experimental parameters on the PtSi film characterics was dicussed, and the optimal experimental parameters were obtained to form high-quality PtSi film. The obtained thickness of PtSi film is just 12nm. The ohmic contact based on low doped p-silicon was investigated. The reproducible and reliable Al/p-Si Ohmic contacts with low specific resistance (ρc～10-5Ωcm2) were prepared succeedly.Fourth, The electrical characteristics of PtSi Schottky barrier diode based on SiNWs have been investigated using current-voltage-temperature (I-V-T) characteristics over a temperature range of 293K-373K. And the Richardson plot of reverse saturation current I0 has been proposed to appropriately evaluate the electrical parameters. The effect of temperature and light on the PtSi/p-SiNWs/p-Si/Al Schottky diode was investigated.The effect of the interfacial layer and series resistance on the electrical characteristics was investgated for the PtSi/p-SiNWs/p-Si/Al Schottky diode. The current transport mechanism in the PtSi/p-SiNWs/p-Si/Al Schottky diode was analyzed by fitting with different current transport mechanism, such as thermionic emission(TE) and field emission(FE).In conclusion, the research method and achievement is to provide important scientific basis for the SiNWs'application in the sollar cell,optical device and infrared photoelectric detector. It must bring a huge economic benefits and social value.