Study On The Photoconductivity And Resistance Storage Performance Of Pure And Sm-doped SnO₂ One-dimensional Nanomaterials

Ultraviolet photodetectors have become the reaearch hotspot of the photodetectors due to its advantages such as small dimension,low energy consumption and high sensitivity.As a kind of typical multifunctional oxide semiconductor,SnO₂ has excellent gas sensitivity and optical properties,it has been widely applied to gas sensors,solar cells,etc.But its micro-nanostructure of the photoconductive and other micro-mechanism is still not clear.Here,we aim to explore high selectivity and sensitivity for UV photodetectors and resistive random access memory based on SnO₂ nanomaterials.The microscopic mechanism was revealed by the systematic experimental analysis,and some properties were modified by rare earth samarium doping.The main conclusions and innovations are as follows:?1?In this thesis,SnO₂ and SnO₂:Sm nanowires were synthesized by high-temperature carbon thermal reduction method and in situ chemical vapor reaction method,respectively.The individual SnO₂ nanowires were prepared as FET devices.The SnO₂ nanowires were n-type semiconductors with an electron mobility of about 220 cm2V-1s-1.?2?The synthesized nanowires were prepared as two-terminal devices.the photoconductivity test shows that SnO₂ nanowires exhibit a strong UV photoconductive response.In addition,the device has a good optical response to visible light at zero bias,indicating that SnO₂ nanowires can be used as self-energizing photodetectors.The photoconductivity of SnO₂:Sm nanowires is inferior to that of pure SnO₂ nanowires,and has obvious sustained photoconductivity.?3?The resistance storage performance test shows that the SnO₂:Sm nanowires have excellent resistance switching effect and the storage performance of the devices is very stable,indicating that SnO₂:Sm nanowires can be used as resistive memory devices.?4?The piezoresistive performance test of static and dynamic strain shows that SnO₂: Sm nanowires have obvious piezoresistive effect.the resistivity of the device decreased under the compression strain,while significantly increased under the tensile strain.SnO₂ nanowires did not show a significant piezoresistive effect.?5?Gas sensing performance studies show that both pure and Sm-doped SnO₂ nanowires have good responsiveness to ethanol at room temperature.The resistivity of SnO₂ nanowires is decreasing,while the resistivity of SnO₂:Sm nanowires is increasing in ethanol.