Preparation And Photoelectric Properties Of Sn-ZnO Broadband Semiconductor Materials

Since the 19th century,the exploration of new energy has never stopped.A functional material with practical application value is called Transparent Conductive Film,which is short for TCO.Because it has good optical transparency and electrical conductivity,it is used in various optoelectronic devices such as light detectors,display screens,and ultraviolet detectors.The most studied and relatively excellent performance is the Semiconductor Oxide Conductive Film,which has significant representative such as In₂O₃,ITO,SnO₂ and ZnO based.In recent years,in-depth research and discussion have found that ZnO thin films have a great influence in society.In order to explore the photoelectric performance application field of metal element-doped ZnO thin films,they have been widely used in more fields such as solar cells and sensors and so on.In this paper,a tin-composite zinc oxide?Sn-ZnO,abbreviation:TZO?thin film material is grown on a quartz target material by magnetron sputtering.The reason for selecting Sn as the doping object is as follows:First,after the Sn⁴⁺replaces the Zn²⁺position release two free electrons.Such advantages are applied to electrical devices to improve their electrical conductivity.Secondly,the ionic radius of Sn⁴⁺is smaller and relatively close to that of Zn²⁺(r_Zn2+=0.074nm,r_Sn4+=0.071nm).This kind of doping makes the lattice spacing change smaller without affecting the optimal growth.Considering the effect of the experimental parameters on the morphology,composition and structure of the film,it was found that the species and concentration of ions in the film material,and the principle of nucleation all affected its surface shape,it was further observed that the effect of enhancing the photoelectric performance in the visible region.Not only has it been improved in terms of linearity,it has also been studied in the field of nonlinear optics,and the application of third-order nonlinear optical properties of thin films has been studied.And carry out research on the following aspects:?1?TZO thin film materials were prepared by direct current?DC?and radio frequency?RF?co-sputtering methods.It was observed that the growth time directly affected the thickness of the film;the DC power directly affected the degree of Sn⁴⁺ion diffusion;the substrate temperature directly affected the film crystal lattice structure.XRD results showed that the obtained thin films contained two characteristic peaks of ZnO and SnO₂,and no other alloy phases existed.SEM results show that the surface morphology of the film is relatively uniform,but there are clusters as the substrate temperature increases.At the same time,EDX data proved the content of each element in the film,and XPS confirmed the valence state of the three elemental components.?2?The photoelectric properties of TZO thin film materials were further studied.First,the effect of Sn content on the optical properties of TZO thin films was analyzed by UV-Vis.The results showed that the band gap was slight changed when the growth time and DC power experimental parameters were changed.The blue shift occurs because Sn⁴⁺doped ZnO replaces Zn²⁺,and more free electrons are released,which increases the number of charge carriers and the Fermi level moves down to the energy band accordingly.The occurrence of the red shift is due to the excess of Sn⁴⁺,which cannot replace the Zn²⁺position,and the free electrons cannot be released when occupying the gap position.At the same time,the HALL results show that as the growth time increases,the Sn content increases,and the carrier concentration is increased,so that the carrier concentration range of the TZO composite film is 10¹⁵?10¹⁹/cm³,which also indicates that the carrier concentration increases when Sn⁴⁺replaces Zn²⁺,it further explains that the blue shift phenomenon occurs with the increase of the band gap.?3?In-depth study of nonlinear optical properties of TZO thin films,and the use of Z-scan technology to analyze the third-order nonlinear absorption characteristics.Under the femtosecond pulsed laser with a wavelength of 532nm,the transition from reverse saturation?RSA?to saturation?SA?appears with increasing sputtering time.And the transition from saturation?SA?to reverse saturation?RSA?appears with increasing substrate temperature.The experimental results show that the order of the third-order nonlinear absorption coefficient is in the range of 10^-7?10^-8m/W,which is expected to be applied to the field of nonlinear optics such as optoelectronic devices.