Optical Properties And Carrier Transport Properties Of Chalcogenide Semiconductor Alloy ZnSSe Nanowires

Group ?-? semiconductor materials are used in various optoelectronic devices because of their wide band gap and energy band structure that can be directly transitioned.However,traditional binary materials such as ZnS and ZnSe have a fixed band gap and cannot achieve continuous spectral response,which greatly limits their application in the field of optoelectronics.Therefore,energy band engineering technology as an effective means to broaden this type of material system has become the research focus of scientific researchers.At present,the ternary alloy semiconductor material ZnS_xSe_1-x has been synthesized.It not only has the excellent photoelectric properties of ?-? semiconductors,but also has an adjustable band gap,which is suitable for the design and manufacture of optoelectronic devices that work at special wavelengths.In recent years,researchers have carried out a series of synthesis and basic properties research around the energy band engineering technology of ZnS-ZnSe.However,the carrier transport characteristics of ZnS_xSe_1-x nanowires have not been systematically studied,and how the energy band engineering technology affects the photoelectric conversion efficiency,photophysical properties and carrier dynamics of this type of material system has not been thoroughly studied.Discussion.Therefore,the systematic study of the photoelectric properties and carrier transport characteristics of ZnS_xSe_1-x nanowires is a prerequisite for the design of optoelectronic devices with superior performance using this type of material system.In this paper,a one-step method was used to synthesize ZnS_xSe_1-x nanowire samples,and the composition,appearance and structure of ZnS_xSe_1-x nanowires were characterized by X-ray diffractometer,scanning electron microscope,and transmission electron microscope.The research results of line optical properties and carrier transport properties are as follows:(1)By analyzing the photoluminescence spectra and low-temperature steady-state photoluminescence spectra of ZnS_xSe_1-x nanowires at different temperatures,it is found that the main PL peak of ZnS_xSe_1-x nanowires is dominated by local excitons before the relative photoluminescence spectrum is 40k(The bound excitons associated with znvacancies),after 40k,the main peak of PL is dominated by free excitons.(2)By analyzing the time-resolved photoluminescence spectra of ZnS_xSe_1-x nanowires,it is found that when the sample is at a low temperature of 6K,the electrons initially generated in a free state jump between the proximal transmission and capturesites,and the electrons are coulombically ground.The bondage is weaker.As the temperature incr eases,the number of recombination paths of excitons increases.These less mobile electro ns will gain more energy,which will cause them to jump to a deepertrap state,resulting in a rapid PL peak dominated by local excitons.Redshift and decrease.At higher temperatures,more and more electrons gain enough energy to delocalize into a free state and recombine with free exciton emission to lead the recombination,resulting in a red shift of PL energy with tempera ture.(3)Analyze ZnS_xSe_1-x nanowires through an optically pumped terahertz system.The rapid decay process is attributed to the capture of surface defects,and it is dominant in the decay of free carriers in ZnS_xSe_1-x nanowires,with slow decay The process is mainly due to non-radiative recombination or band recombination related to structural defects.(4)The contact printing method was used to synthesize ZnS_xSe_1-x nanowire fieldeffect transistors.The nanowires have obvious gating effect,which proves that the device structure realizes the regulation of gate voltage and is an N-channel MOSFET type.