Fabrication And Application Of Laser Interference Backward Transfer Gold/Silver Nanoarray Structure

Laser interference induced backward transfer(LIIBT)is a new technology produced by the combination of laser induced backward transfer and laser interference technology.As a new laser micro-nano fabrication technology,LIIBT has many advantages,such as wide application range,low cost,high efficiency,no pollution and can be implemented in atmospheric environment.Using a short pulse laser as light source,a large area of micro-nano structures and subwavelength particles can be prepared on the surface of the receiving substrate under atmosphere condition.Based on the principle of pulsed laser deposition,this paper proposes a theoretical model of the two-beam LIIBT,and studies the influence of parameters such as laser fluence,pulse number and film thickness on the backward transfer of laser interference.Au and Ag micro-nano stripe structure with surface enhanced Raman scattering effect was successfully prepared under atmospheric conditions.The main work of this paper is as follows:(1)The theoretical model of two-beam LIIBT was established.The mechanism of each stage of the pulsed laser deposition process was analyzed.The characteristics of each stage of the LIIBT process and the influence of experimental conditions were studied.Based on the basic principle of the pulsed laser deposition,a theoretical model of the backward transfer of metal micro-nano stripe structure by two-beam LIIBT in atmospheric environment was established.The formation and mechanism of Au and Ag micro-nano stripe were discussed in the thesis.(2)The effects of laser pulse number and laser fluence on the structure of micro-nano stripe structure were investigated.Using Nd:YAG nanosecond laser,the transfer experiments of Au and Ag thin films on the surface of glass were carried out.In the experiment,the number of laser pulses were 1,5 and 10,and the thickness of the films were 30nm and 50nm,respectively.The laser fluence of the transferred gold films were 123-177m J·cm^-2 and the transferred silver films were 141-195m J·cm^-2.Micron-scale periodic stripe structures composed of evenly distributed nanoparticles were successfully fabricated on the surface of glass.After analyzing and characterizing by SEM and EDS,the experimental results are consistent with the theoretical model.(3)Raman enhancement effect of micro-nano stripe structure on organic compounds was studied.SERS of Au and Ag micro-nano stripe structure was measured by Raman spectrometer.It was found that the SERS of the Au and Ag micro-nano stripe structure was obvious for Rhodamine B and ciprofloxacin at the concentration of 10^-8M.The silver micro-nano stripe structure also showed a significant SERS effect on profenofos.A new Raman enhanced substrate chip is provided for high sensitivity detection of food engineering and water pollution.