Preparation,and Photoelectric Properties Of Two Dimensional Non-layered Telluride Thin Films

Due to its excellent electrical,optical and mechanical properties,2D non-layered tellurite materials represented by Cd Te and Sn Te have a broad application prospect in the development of new photoelectric devices.However,due to the isotropic structural characteristics of Cd Te and Sn Te,the growth of large-area and high-quality single crystal film is facing great challenges,which seriously limits the practical application in the field of optoelectronic devices.Based on the above research background,the large area Cd Te and Sn Te films were prepared by DC magnetron sputtering technology.Further,the structure,properties and optical response mechanism of these films were investigated in detail.The main research contents are as follows:Firstly,the epitaxial growth of Cd Te and Sn Te thin films was realized by DC magnetron sputtering,and large area single crystal films were obtained.The result showed that the films were uniform,and the atoms on the surface were arranged periodically and regularly.Moreover,the growth orientation of the films was controllable in this work.The acid-free exfoliating process could be used to realize a large area of non-destructive exfoliation of the film,which further demonstrated the uniform continuity and high crystallinity of the prepared film in a large area.Secondly,Cd Te photodetectors were prepared and the photoelectric performance of the devices were studied.The result showed that the as-fabricated devices exhibited a good response at room temperature with the responsivity,detectivity,and short rising/falling times of 2.37 AW^-1,1.99×10⁷ cm Hz^1/2W^-1 and 0.14/0.16 s,respectively.Comparing with similar photodetectors,its performance had been greatly improved.Further analysis showed that the improvement of the performance is due to the high crystalline quality and low defect density of the films.Then,based on the excellent photo-thermal and thermal-electrical conversion properties of Sn Te,the Sn Te photothermoelectric detectors were designed and studied.Due to the excellent PTE effect,the devices had self-driven function and achieved a broadband spectral response in the range of 404 nm-10.6μm.Moreover,the devices had an ultra-low dark current of 2.3 p A at room temperature,showing a high optical switching ratio of more than 10⁵,which was 4-5 orders of magnitude higher than other reported Sn Te detectors.At the same time,the devices yielded the high detectivity of¹.3×10¹⁰ cm Hz^1/2W^-1and short rising/falling times of⁷8/84 ms.Furthermore,the photodetector transferred onto the flexible template exhibited excellent mechanical flexibility.These findings offer feasible strategies toward designing and developing low-power-consumption wearable optoelectronics.In summary,the research on the growth and photoresponse properties of non-layered telluride films provides a new strategy for its large-area preparation and transfer,and provides a new research idea for the development of high-performance and broadband photodetectors.