Regulation Of Surface States Of One-dimensional ZnO Nanostructures And Its Applications In Self-powered Light Detectors And Temperature Storage

For ZnO nanostructures,the band gap is wide and the bound energy of exciton is large.It has more extensive application prospect because of its many preparation methods and simple preparation process,especially in the field of ultraviolet photoelectric detector and memory.So it has gradually become the hot research material of the third generation semiconductor materials.In this paper,we prepared pure ZnO nanowires by physical vapor deposition method,and then we constructed a two-terminal device based on a single ZnO NW with two same Ag electrodes to study their electrical transport performance,optical response performance and storage performance.Here are the main findings:In terms of electrical transport performance,the electrical transport performance of the device is not very stable,and it is easy to be affected by various external factors.In this paper,we controled the external unidirectional/bidirectional bias to precisely control the electrical transport performance of a dual-terminal electronic device based on a single ZnO nanowire with two identical electrodes.For a single nanowire-based two-terminal electronic device,two diodes with back-to-back series resistors are formed.The width and height of the surface barrier can be well adjusted by filling and releasing traps near the two electrodes.In addition,at low operating bias and at room temperature,the fill and empty states of traps can be well maintained,resulting in adjustable non-volatile storage characteristics.In terms of light response performance,the individual ZnO nanowire-based device shows strong light response in the ultraviolet area,we can change the barrier height of the device through applying certain bias to device.After modulation,it was favorable for the modulated thin surface barrier with filled traps to rapidly separate photoexcited electron-hole pairs,which in turn could improve photodetection performance with fast response and recovery speed and meanwhile realize self-driven photodetection function.In the aspect of information storage,most of the resistive random access memory is written by external bias.In this paper,a temperature memory written by temperature was prepared and the giant thermal resistance effect based on ZnO nanowire was explored.When applying high temperature,the electrons that are injected into traps from negative electrode can escape from the traps.With the rise of temperature,the depth of the trap also increased,the device gained different resistance states.When the temperature returned to room temperature,the electrons can be injected into traps from negative electrode again after applying certain bias,then the device got back to the initial state,so as to realize a temperature storage which is written by temperature and erased by applied bias.