Fabrication Of The 1D-ZnO Piezo-photoelectric Device And Investigation Of The Optical Properties Of ZnO Core/shell Structure

ZnO is direct and wide band-gap semiconductor material with hexagonal wurtzite struc-ture.Researchers have prepared ZnO using different ways,which make ZnO existing in dif-ferent shapes,for example,ZnO nanoparticles,ZnO nanowires,ZnO nanoribbons and ZnO nanoscale combs,etc.1D-ZnO nanowires have many excellent properties.It also can achieve perfect crystal free growth and have good crystallization quality,its tenability about diameter and length,large specific surface area,strong electromechanical coupling characteristics and perfect optical performance.First,piezo-phototronic effect is a new physical effect based on the coupling of semi-conductor,piezoelectric polarization and photoexcited phase.This effect can greatly improve the optoelectronic performance of semiconductor devices.1D-ZnO nanorods with high crys-tallization quality were prepared by chemical hydrothermal method.A pressure sensor with n-ZnO nano-arrays/p-Cu₂O film structure is fabricated on flexible Cu foil substrate.The commercialized GaN LED with the central emission wavelength of 405 nm is tactfully em-bedded in the pressure sensor acting as the illumination source,which will greatly decrease the device size and reduce energy consumption as well as fabrication cost.We systematically study the performance of the pressure sensor based on piezo-phototronic effect.The hetero-structure shows a nearly ideal rectification characteristic with forward current more than 1mA?at 3V?under pressure without illumination.The linear increase in SR with the applied pressure observed in the pressure sensor.The sensor exhibits rapid response/recovery cha-racteristics under pressure.Moreover,when the illumination intensity is 11.7 mW/cm² and under the same pressure,the highest enhancement of the SR and sensitivity of the pressure sensor can reach up to 376%and 918%,respectively.Second,1D-ZnO material had a large number of surface defects which destroys its opt-ical property.In order to improve the optical properties of 1D-ZnO nanowires,a technique was used to passivate the surface of ZnO nanowires with sputtering specific semiconductor materials to form a core-shell structure,which improves the surface properties of 1D-ZnO na-nowires and their optical properties.The PL spectra of ZnO nanoarrays coated with SnO,NiO and ZnO were compared with bare ZnO nanowires.The effect of surface passivation on opti-cal property of Zn O nanoarrays was investigated.The core-shell structure of ZnO/SnO was compared with untreated ZnO nanoarrays.The ratio of UV to visible of ZnO/SnO increased by 200%comparing with untreated ZnO nanoarrays',and the emission peak of deep level de-creased with the increase of shell's thickness.Compared with untreated ZnO nanoarrays,NiO/ZnO and ZnO/ZnO core-shell structure are regulated by the effect of surface passivation.The UV/visible ratio is increased by 70%and 30%respectively.