Preparation And Photoelectric Detection Performance Of Gallium Nitride Microstructures And Nanostructures

In recent years,with the emergence of new technologies such as artificial intelligence and 5G,it indicates that human society has transformed into a comprehensive digital era,which has put higher demands on high-density,large-capacity,and fast communication technologies.As a key component that converts optoelectronic signals,the performance of optoelectronic detectors,such as responsivity,response speed,and signal-to-noise ratio,plays a decisive role in the speed and accuracy of data reception by backend devices.It is a critical factor that must be considered to achieve high-speed,large-capacity optical communication systems,GaN as a typical third-generation semiconductor,has achieved great success in the above fields.Importantly,due to the unique properties of wide bandgap,high electron mobility,good thermal stability,easy integration,high-temperature resistance,and radiation resistance,GaN is suitable for producing solid-state ultraviolet（UV）detectors with small size,low power consumption,and good chemical and physical properties.With the development of the times,the detection ability of GaN-based optoelectronic detectors has been greatly improved.However,due to the limited absorption of incident photons by planar GaN materials,the responsivity of traditional structured GaN detectors is usually lower than 1 AW^-1,which cannot meet the requirements of high responsivity and fast optoelectronic conversion in practical applications.The rapid development of nanotechnology provides a new approach to improve the performance of GaN-based detectors.This paper is based on the preparation of GaN micro-nanostructures,designing and developing a new type of high responsivity and fast response GaN-based optoelectronic detector,and the main research progress achieved is as follows:1.An optoelectronic detector with a composite porous GaN structure and gold nanoparticles（AuNPs）was developed.Based on planar GaN thin films,a porous GaN structure can be achieved through electrochemical etching technology to enhance the capture ability of incident light.A series of nanoporous GaN samples with different porosity rates were produced by etching,and the light extraction performance of GaN was improved through a large number of pores.Gold nanoparticles were prepared by sodium citrate reduction and were combined with the porous GaN structure to obtain a new type of optoelectronic detector,the AuNPs/porous GaN.According to the theory of rapid hot hole injection in p-GaN and local surface plasmon resonance of gold nanoparticles,the responsivity of the device was improved and the response time was shortened.Using FDTD simulation,the generation of local surface plasmon was simulated and confirmed that the responsivity of the detector increased to 1700 m A/W,which is 30 times higher than that of traditional GaN detectors.The response time was reduced to 58 ms/121 ms,and it has an excellent on/off ratio（>10⁴）.2.A photodetector with BaTiO₃ composite GaN structure has been developed.The surface hydrophilicity of GaN was modified by the method of lauric acid and ultraviolet irradiation,and BaTiO₃ film was deposited on the surface of GaN after appropriate etching.Based on this,a high-efficiency self-powered BTO/GaN ultraviolet photodetector（UV PD）with thermoelectric and photoelectric effects,high response rate,and fast response speed was formed.The film formation process was improved by controlling the interface contact through X-ray diffraction technology and Raman spectroscopy characterization.By reducing the response time through the internal polarized electric field of GaN and BTO,higher response and shorter response time of140 ms/200 ms were obtained under the condition of pre-polarization with applied bias.The principle analysis of enhancing device response through the application of a cooling system was conducted.