Preparation And Properties Characterization Of Infrared Silicon-based Thin-film

Due to good electrical properties and comparatively perfect and low-cost preparation techniques,the silicon has become the most fundamental material in optoelectronic and integrated electronic industry.However,limitations like the indirect band gap and the fixed and non-tunable optical constant have made its optical characteristics not so good,especially in the infrared band.Therefore,silicon-based doping is adopted as the usual way to re alize its application in the infrared band.Si_1-xSn_x thin film was prepared by metal Sn doping,and change rules of the SEM image,Raman spectra and optical and electrical properties of the deposited Si_1-xSn_x film were studied under the condition of different preparation time,growth temperature and Sn content.In addition,Te/Si_1-xSn_x structure was prepared on the basis of Si_1-xSn_x film.The microstructure,optical and electrical properties of Te/Si_1-xSn_x structure were studied and some conclusions can be obtained as follows:Preparation of Si_1-xSn_x film using radio frequency magnetron sputtering film technology,SEM image shows the best preparation time and temperature of Si_1-xSn_x film is 30min and 150?.The changes in the structure of the a-Si network caused by the change in the Sn content were studied in detail.It was found that the increase in the Sn content resulted in a decrease in the ordering of the a-Si network.The increase of preparation temperature can promote the crystallization of a-Si.The mechanism may be MIC mechanism.With the increase of Sn content in Si_1-xSn_x film,the resistivity of Si_1-xSn_x film decreased continuously,and the change rule of its brightness and darkness conductivity increased first and then decreased.By controlling the temperature,the Si_1-xSn_x film can have a low resistivity.The optical bandgap of Si_1-xSn_x thin films tends to decrease linearly with increasing Sn content.In order to better study the performance of Te/Si_1-xSn_x structure,we studied the preparation conditions of Te film.The continuity of the Te film prepared at room temperature is good,and the increase of the preparation temperature will make the surface of the Te film form nanostructures.As the preparation temperature increases,the surface nanoparticle size firstly becomes smaller and then becomes larger.The transmittance of Te films with different film thicknesses was more than 66%in the near-infrared band.Samples of the Te/Si_1-xSn_x structure exhibit a reflection peak at2150nm.The near-infrared absorption rate of all Te/Si_1-xSn_x structures increases with the increase of wavelength,and shows a trend of increasing first and then decreasing with the preparation temperature.The IV curve shows that the Te/Si_1-xSn_x structure does have some electrical characteristics of the pn junction,while an excessively high preparation temperature?250??can destroy the structural characteristics of the pn junction of the Te/Si_1-xSn_x structure and make the electrical properties similar.