Preparation And Optical Properties Of Zn And Li Doped Ga₂O₃

Gallium oxide(Ga2O3)nanostructures have broad application prospects in solar cells,miniature electronic switch,and ultraviolet photodetectors because of the stable physical and chemical properties,excellent photoelectric properties,wide band gaps,and so on.In general,Ga2O3 nanomaterials are mostly n-type semiconductor structures,and it is difficult to find p-type structures,which restricts the research and application of related devices.In this paper,Zn-doped Ga2O3 and Li-doped Ga2O3 nanomaterials were synthesized by thermal evaporation method through controlling the doped Zn or Li elements and the growth environment.Then the scanning electron microscope(SEM)was used to observe the morphology of the prepared samples,the Raman spectra of the samples were analyzed to characterize the structure of the samples,and the optical characteristics of the samples were analyzed by photoluminescence(PL).It is found that:(1)The emission of Zn-doped Ga2O3 is mainly green light.The luminous intensity of the samples will change with the increase of Zn content.When the doping ratio of the raw material is less than 6:1,the light emission intensity becomes strong,and when it is more than 6:1,the light emission intensity becomes delicate.From the PL spectra of the samples,it can be inferred that the Zn-doped Ga2O3 nanostructure can be converted into a p-type semiconductor structure.(2)The PL spectra of Li-doped Ga2O3 will be dominated by red light emission at room temperature.After analyzing the temperature-dependent PL spectra of the samples,it was found that the luminous intensity will become stronger and stronger as the temperature decreases,and more peaks will be split at low temperatures.Based on the Raman spectra of the samples,we believe that it is caused by the 1s23s-1s27p transition of Li ions.(3)Based on the experiment of Li-doped Ga2O3,we found that when the proportion of Li element in the raw material is too high,the prepared samples will be lithium gallate(LiGaO2 and LiGa5O8)structures.Moreover,LiGa5O8 is easier to synthesize in air atmosphere,and more suitable for synthesizing LiGaO2 in the argon atmosphere.After characterizing the samples with PL,it was found that the red emission of lithium gallate and the red emission in the PL spectra of Li-doped Ga2O3 are both caused by Li ions doped into the crystal lattice.Besides,this doping can change the band structure of Ga2O3,thereby converting it into p-type semiconductor nanomaterials.We also used samples containing Li element to prepare simple optoelectronic devices The CGS-MT optoelectronic was integrated test platform to analysis the electrical characteristics of the samples.It is found that the resistance of the samples after light exposure is related to the photoluminescence wavelength of the samples.This will help further research on Ga2O3 nanostructured devices.