Preparation And Ultrafast Dynamics Research Of MnSi_1.7 Nanofilm For Biosensor

Biosensor is a kind of test instrument which is sensitive to some specific biological materials and transform the concentration of these materials into electrical signals.In contrast to traditional test methods,biosensors have the advantages of faster response speed,higher recognition precision,and much smaller.A biosensor consists of two parts: 1.biological molecules sensoring element?such as enzyme,DNA,biological membrance,histocyte,antibody et al.?.2.Transducer which can turn other signals into electrical signal.In the two main parts,transducer determines the sensitivity and accuracy,so the physical properties research of the transducer would be useful for the development of biosensor.In this article,we mainly focus on the ultrafast dynamic property of MnSi_1.7 nano thin film which could be used as the transducer.The research contents are as follows:?1?Preparing the MnSi_1.7 nano thin film by using magnetron sputtering method,and then the sample was characterized;?2?Using femtosecond laser pump-probe technique to measure the transient reflectivity change,the data of different pulse energy was obtained.?3?Through the quantitative calculation of the initial carrier density,the influence of the carrier numerical density on the initial reflectivity was obtained,and we also compared it to the experimental data to verify the accuracy of the calculation;Double exponential model was used to fit the decay process,and the results shows that the fast decay process last about 0.6ps,in which the carrier-carrier scattering is the main process.The slow decay process last about dozens of picosecond,and the carriers recombination and diffusion play domain the process.