Preparation And Electrical Properties Of Ba SnO₃-based Perovskite Transparent Conductive Films

Transparent conductive oxide?TCO?film exhibites the characteristics of forbidden bandwidth,good electrical conductivity and high visible light transmittance,which make it show great application value and huge market demand in the fields of flat-panel displays and solar cells.In₂O₃:Sn?ITO?and SnO₂:F?FTO?have achieved large-scale commercialization.However,the lack of rare element leads to a high cost of ITO,which limits its use.FTO is corrosively doped with F^-and difficult to etch and reprocess.In addition,the commonly used TCO film can not meet the development of optoelectronic special devices such as full perovskite ferroelectric memory,full perovskite ferroelectric field effect tube,etc.,and requires a new type of TCO film.Therefore,it is imperative to develop new transparent conductive materials with high performance and low cost.The perovskite oxides are simple in structure and easy to be doped.Its application in all-perovskite devices can solve the problem of interfacial lattice mismatch and is expected to promote the development of the field of optoelectronics.Therefore,the TCO thin films with perovskite structure have been widely studied in recent years.In this paper,?001?oriented SrTiO₃?STO?single crystal was used as the substrate,and Nd_xBa_1-xSnO₃?x=0,0.03,0.05,0.07,0.09?,La_xBa_1-xSnO₃?x=0,0.03,0.05,0.07,0.09,0.11?,and A_0.07Ba_0.93SnO₃?A=La,Nd,Sm,Er?films were grown on the single crystal substrate by pulsed laser deposition?PLD?,respectively.The effects of preparation process,rare earth element doping type and doping amount on the properties of the films were investigated,mainly engaged in the following two aspects.?1?The effect of the preparation process on the properties of the film was investigated.The pure phase Nd_0.07Ba_0.93SnO₃ target was prepared by the traditional solid phase sintering method.The Nd_0.07Ba_0.93SnO₃ film was prepared on STO single crystal,The preparation of oxygen pressure,deposition temperature and film thickness on film structural properties,electrical properties and optical properties were investigated.The optimum preparation conditions of Nd_0.07Ba_0.93SnO₃ film with preparation temperature of 825 ^oC,deposition oxygen pressure of 10 Pa and sputtering time of 30 min were determined.Under this process condition,the film quality,conductivity and light transmission were excellent:a full width at half maximum of0.108^o,the room temperature resistivity is 0.5 m?cm,the carrier concentration is5.04?10²⁰/cm³,the mobility is 24.87 cm²/Vs,and the transmittance under the visible light region is greater than 80%.?2?Under the optimal preparation process,Nd_xBa_1-xSnO₃?x=0,0.03,0.05,0.07,0.09?,La_xBa_1-xSnO₃?x=0,0.03,0.05,0.07,0.09,0.11?,and A_0.07Ba_0.93SnO₃?A=La,Nd,Sm,Er?films were prepared on STO single crystal substrate by changing the rare earth element doping type and the content of doping elements.The effect of Nd and La doping amounts and doping elements?La,Nd,Sm,Er?on the properties of BaSnO₃-based films were analyzed.According to the experimental results,the film crystallinity and electrical properties were improved with the increase of Nd doping amount.When the Nd content is higher than 7%,the film performance is decreased.As for the same doping amount,the La-BaSnO₃ film has the best properties,and the performance of film declines with the decrease of the ionic radius of the doping element.When the doping amount of La reaches at 5%,the electrical properties of the film are optimized.What is more,with further continual increase of the doping amount,the film properties slightly reduce.The data results provide a theoretical basis for further improving the performance of BaSnO₃-based films.