Research On Photoelectic Characteristics Of InSb Film Grown By Sputtering

InSb has the narrowest gap of the III-V binary semiconductor materials and a lot of application value in the mid-infrared.With more concern in the study of the amorphous,amorphous films have performed a lot of properties that crystalline ones don`t have.Therefore,there is much value to research in amorphous InSb film meticulously.This article has mainly researched on InSb films grown by magnetron sputtering and studied on the photoelectric characteristics.There are the main contents below:Firstly,technological parameters of the growth of InSb films were optimized by adjusting sputtering power and pressure,in which 16 groups of films were prepared.As the result of measurements through X-ray diffraction(XRD)and atomic force microscope(AFM),the best technological parameters were ascertained.They were 2.5 Pa(pressure)and 100 W(power)in polycrystal films,2.0 Pa and 60 W in amorphous films with high degree of disorder and 0.5 Pa and 60 W in amorphous films with high degree of disorder.Secondly,photoelectric characteristics of the polycrystal film have been tested and studied.Optical transmission spectrum was tested by FTIR spectrometer and studied by the means of envelop.The optical gap of the InSb film grown on Si substrate is 0.26~0.27 eV,which has a blue shift of 0.08 eV compared with the standard gap(0.18 eV).Electric characteristics were tested by Hall Effect Measurement System.Resistivity was taken the logarithm and matched with the temperature.It was found that lgρ and T have linear relation from 100 K to 300 K.Finally,photoelectric characteristics of the amorphous film have been tested and studied.Absorptivity(α)was abtained by the means of envelop by which the Urbach Energy was ascertained 0.12 eV.Resistivity was also taken the logarithm and matched with the temperature.It was found that lgρ and T1/2 have linear relation from 140 K to 200 K,which matches well with ES variable range hopping(VRH)conduction and lgρ and T1/4 have linear relation from 260 K to 330 K,which matches well with Mott VRH conduction.Using the difference of VRH conduction,change of conduction type and mobility could be well explained.