Preparation And Thermoelectric Properties Of Molybdenum Oxide And Bismuth Telluride-based Compounds

In recent decades,thermoelectric materials have been studied in depth,and thermoelectric devices have also been widely used in the fields of refrigeration and power generation.With the rise of wireless sensors and communication technologies in the fields of electronics,medical care,industry,etc.,people have increasingly higher requirements for the performance of wireless devices.Thermoelectric thin films have good application prospects in the manufacture of micro sensors,micro power sources,and some small devices due to their small size and strong flexibility.The improvement of thermoelectric film performance is of great significance to the production and application of thermoelectric devices.1.The choice of substrate can greatly affect the performance of the thermoelectric film.In the previous work,we have grown a MoO_2+x thin film with good performance on a Sisubstrate with a power factor of 1.78 m W/?m·K²?at 700 K.Studies have shown that the significant enhancement of Seebeck coefficient mainly comes from the contribution of Sisubstrates.In this paper,according to the parallel conduction model,by adjusting the thickness of the MoO_2+x film in the MoO_2+x/Sisystem,the contribution ratio of the Sisubstrate to the Seebeck coefficient can be changed,thereby optimizing the power factor.Finally,the highest power factor was obtained in the 130 nm thick film sample,reaching 12.5 m W/?m·K²?at 668K.The experimental results show that the effective thermoelectric properties of the film will be affected by the interface layer between the substrate and the film.The presence of Moin the MoO_2+x film may limit the formation of the SiO₂interface layer.These results provide a simple,low-cost,and scalable technical route for exploring high-performance thermoelectric devices.2.It is of great significance to improve the thermoelectric properties of bismuth telluride based thermoelectric thin films for their industrial application.In this paper,Bi_0.5Sb_1.5Te₃/PbTe composite films with high orientation were prepared by magnetron sputtering.By adjusting the amount of PbTe and changing the carrier concentration,the conductivity can be improved.Annealing can optimize the crystallinity of the films,and the second phase of PbTe was found in the recrystallization process.In addition,the carrier concentration and mobility are greatly improved by annealing,and the conductivity and Seebeck coefficient of the films are optimized.The experimental results show that the power factor of Bi_0.5Sb_1.5Te₃+0.5%PbTe is 2.06 m W/?m·K²?at 480 K,which is about 7 times of that of Bi_0.5Sb_1.5Te₃ film substrate.