Surface Plasmon Enhancement Study Of Laser Characteristics Of GaN Suspended Microcavity

Gallium Nitride(GaN)alloy is receiving more and more attention as a promising candidate material for optoelectronic device applications due to its wide direct band gap(up to 3.4e V)at room temperature,especially ultraviolet(UV)lasers..In particular,the GaN Whispering Gallery Mode laser confines the light in the microcavity through the total reflection effect of the light.Its optical loss is very small,and it has a lower threshold and a higher quality factor.The size of the microcavity,the boundary shape of the cavity,and the refractive index of the medium inside and outside the cavity directly affect the performance of the WGM laser.Therefore,studying the limiting effect of different microcavity shapes,sizes and refractive indexes on lasers is of great significance for discussing and predicting the properties of microcavities and designing microcavities with specific properties.The integration technology of GaN devices is of great significance for solving the problem of on-chip light sources.In order to improve the optical characteristics of GaN microcavity lasers,this paper first studies the influence of the thickness of GaN microdisks on its optical performance,and then studies from the perspective of surface plasmons The influence of surface plasmons on the optical gain and intensity of GaN microdisks.In addition,there are some studies on the electroluminescence of GaN microdisks.This article mainly conducted three studies on GaN microdisks.One is the variation of GaN microdisk performance with the thickness of the microdisk.The dry GaN and isotropic wet etched silicon methods are mainly used to prepare 5?m diameter silicon pillars supporting floating GaN microdisks.In order to clarify the influence of microdisk thickness on device characteristics,WGM lasers in the ultraviolet range of four different thickness GaN microdisk devices were studied.The performance of the device is given,including quality factor Q,lifetime,and laser modulus.The half maximum width(full width at half maximum),quality factor Q and laser modulus of different thicknesses are calculated from the PL spectrum.Observing the life of the device through time-resolved spectroscopy,the quality factor Q of the device first increases,and then decreases as the thickness decreases.Compared with the device before etching,the device life after etching is shorter.The second is the surface plasmon enhancement study of GaN suspended microcavity laser characteristics.Through various spectral characterization techniques such as micro-area spectroscopy,absorption spectroscopy,and Raman spectroscopy,the optical properties of GaN and metal nanoparticles and their composite systems have been systematically studied.GaN microdisks are made by photolithography and ICP etching.The surface of the GaN microdisks is plated with metal Al by magnetron sputtering,and then the device is tested and characterized,including EDS energy spectrum analysis,PL spectrum,quality factor Q value calculation,laser mode number Calculation,life test,through test analysis,it is found that the threshold value of the device after vapor deposition of Al is reduced,the laser intensity is enhanced,and the life span is not changed much,mainly due to the formation of a local surface plasmon effect on the surface of the device,thereby realizing the enhancement of laser intensity.The third is in addition to the research on the photoluminescence of GaN microcavities,there is also the research on the electroluminescence of GaN devices.The main production of 100?m GaN-based wheel-shaped microcavity light-emitting diodes(LEDs),its peak emission The wavelength is 438 nm,and another emission peak can appear at 512 nm by coating CH₃NH₃Pb Br₃on the LED.The LED based on the wheel-shaped microcavity is made by photolithography and inductively coupled plasma etching process.The photoelectric performance of the device is characterized by EL spectrum,luminous intensity,full width at half maximum and 3 d B bandwidth.It is different from the one without CH₃NH₃Pb Br₃layer.Compared with the device,the device has dual-band luminescence and a higher 3d B bandwidth,so this research has potential applications in optical communications.The thesis first studied the change of GaN microdisk performance with the thickness of the microdisk,then the surface plasmon enhancement study of the GaN suspended microcavity laser characteristics,and finally introduced some research on GaN devices on electroluminescence.The research of this thesis is The design and preparation of microcavity lasers provide important technical support,which is of great significance for the design of new GaN-based WGM lasers.