Study On Preparation And Ultraviolet Detection Properties Of MZO Nano Films

With continuous revolution and innovation of science and technology,traditional semiconductor materials can no longer meet the needs in many fields such as imaging display,storage,detector etc.Therefore,to keep up with the advanced research and application in semiconductor field,the scientists are eager to find a qualified wide band-gap material,in which case,the MZO(Magnesium Zinc Oxide)Nano-material has been given extensive attention lately because of its wide band-gap modulation(3.37?7.83 eV)and excellent photoelectric performance.Especially in the field of ultraviolet detection,the wide optical band gap of MZO film has made it possible to cover the whole ultraviolet band Other than this,it has strong radiation resistance and good transmittance of visible light.Therefore,the ultraviolet detector based on MZO thin film has great application value.In this research thesis,firstly,several groups of MZO films were prepared by sol-gel method with different processing parameters.The films were studied with the characterization by SEM and XRD.After that,I used standard lithography technology to make MSM structure MZO film ultraviolet detection module,and then characterized and analyzed its photoelectric performance.Detailed research work are as follows:(1)Preparing multi-group MZO nano-films on quartz and silicon substrates by sol-gel method.During the preparation the process parameters were adjusted.Systematically studied the effects of composition and annealing temperature on the surface morphology of MZO films.And giving insight into the effect of Mg content on the phase structure and optical band gap of MZO films.(2)Through a self-built square resistance measurement system investigating the effects of composition and annealing temperature on the high resistance properties of MZO thin films.It was found out that the magnitude of the square resistance of MZO films increased from 1010 to 1012 with the increase of Mg content.Combining with the physical mechanism and MZO films microstructure,the effects of composition and annealing on the high-resistance properties of MZO thin films were analyzed comprehensively.(3)The MZO ultraviolet detection module of MSM structure with different Mg content was prepared by standard lithography process such as wet etching.Based on Schottky contact barrier and other related physical mechanisms,systematically studying how different Mg content influenced the photoelectric properties of MZO ultraviolet detection module.The results yield that with the increase of Mg content in MZO films,the surface morphology becomes more dense and homogeneous;the average surface roughness Ra decreases as well.The surface morphology of MZO films can be improved by annealing at 350 ?.Moreover,the square resistance of MZO films with regulation of Mg content at 10%?40% from 1.648×1010 ?/??2.602×1012 ?/? at 450 ? annealing temperature.Increasing Mg content and annealing temperature will make MZO films exhibit larger high resistance properties.With the increase of Mg content,the dark current of MZO ultraviolet detection module decreases from 4.56 nA to 33 pA at 8 V bias voltage.Peak response decreased from 0.086 A/W to 1.62 mA/W at 25 V bias.It's mainly due to the increase of Schottky barrier height and square resistance of MZO films that the responsiveness of detection module decreases.