| In recent years,semiconductor metal oxides have been widely studied and applied in solar cells,photocatalysts,and photodetectors.Among these metal oxides,the non-stoichiometric monoclinic phase W18O49 has narrow band gap.wide range of light absorption wavelengths and excellent electrical conductivity,so W18O49 has wide application prospects in the fields of clean energy,photocatalytic degradation of pollutants,photodetector technology and photochromism.In this paper,W18O49 nanomaterials,CsPbBr3 and other related materials were prepared and characterized.MSM photodetectors based on CsPbBr3,W18O49 and other materials was designed.The photoelectric performance of these MSM photodetectors has been characterized.The research was carried out as follows in detail:(1)CsPbBr3 material was synthesized by spin coating method.The CsPbBr3 material was characterized by XRD,SEM and UV-vis.The results show that the monoclinic phase CsPbBr3 nanosheets with a light absorption cutoff wavelength of 539 nm were prepared.MSM CsPbBr3 photodetector was fabricated using CsPbBr3 nanosheets.The performance of the MSM CsPbBr3 photodetector was studied by I-t curve.The results show that the MSM CsPbBr3 photodetector has a dark current of 0.6 nA under 1 V bias voltage.Under the irradiation of 17.6 W xenon lamp,the rising response time of photocurrent was 0.2 s,the falling response time of photocurrent was 0.1 s,the steady state photocurrent was 0.6 nA,the signal-to-noise ratio was 1,and the light responsiveness was 3.41 × 10-11 A/W.(2)TiO2 nanomaterials were synthesized by sol-gel method.The TiO2 nanomaterials were characterized by XRD.The results show that anatase phase TiO2 was prepared.MSM TiO2/CsPbBr3 photodetector was fabricated using TiO2 nanomaterials and CsPbBr3,and its properties were studied by I-t curve.The results show that the MSM TiO2/CsPbBr3 photodetector has a dark current of 10.5 nA under 1 V bias voltage.Under the irradiation of 17.6 W xenon lamp,The rising response time of photocurrent was 0.1 s,the falling response time of photocurrent was 0.1 s,the steady state photocurrent was 114.5 nA,the signal-to-noise ratio was 10.9,and the light responsiveness was 6.51×10-9 A/W.(3)W18O49 material was synthesized by solvothermal method.The W18O49 material was characterized by XRD and SEM.The results show that the monoclinic phase W18O49 nanowires were prepared.MSM W18O49/CsPbBr3 photodetector was fabricated using W1849 nanowires and CsPbBr3.The light absorption properties of the photosensitive layer of the MSM W18O49/CsPbBr3 photodetector were studied.The results show that the W18O49 nanowire layer increased the photo absorbance of the photosensitive layer by about 0.2.The performance of the MSM W18O9/CsPbBr3 photodetector was studied by I-t curve.The results show that the MSM W18O49/CsPbBr3 photodetector has a dark current of 0.35 nA under 1 V bias voltage.Under the irradiation of 17.6 W xenon lamp,the rising response time of photocurrent was 0.3 s,the falling response time of photocurrent was 0.2 s,the steady state photocurrent was 200 nA.the signal-to-noise ratio was 570,and the light responsiveness was 11.34x 10-9 A/W.(4)W18O49 material was synthesized by atmospheric reduction method.The W18O49 material was characterized by XRD and SEM.The results show that the monoclinic phase W18O49 nanorods with high phase purity and anisotropy were prepared.The W18O49 material were coated with TiO2 nanomaterials prepared by(2).The W18O49@TiO2 were characterized by TEM.The results show that the TiO2 nanomaterials formed uneven coating on the surface of nanorod.MSM W18O49@TiO2/CsPbBr3 photodetector was fabricated using W18O49@TiO2 and CsPbBr3.The light absorption properties of the photosensitive layer of the MSM W18O49@TiO2/CsPbBr3 photodetector were studied.The results show that the W18O49@TiO2 layer improved the photo absorbance of the photosensitive layer by about 0.9.The performance of the MSM W18O49@TiO2/CsPbBr3 photodetector was studied by I-t curve.The results showed that the prepared MSM W18O49@TiO2/CsPbBr3 photodetector has a dark current of 0.25 nA under 1 V bias voltage.Under the 17.6 W xenon lamp,the rising time of photocurrent was 0.1 s.the falling time of photocurrent was 0.2 s,the steady state photocurrent was 210 nA,the signal-to-noise ratio was 847,and the light responsiveness was 11.93 × 10-9 A/W.Compared with the MSM CsPbBr3 photodetector produced in this paper,the optical response of the MSM W18O49@TiO2/CsPbBr3 photodetector was improved by 350 times and the signal-to-noise ratio of the MSM W18O49@TiO2/CsPbBr3 photodetector was improved by 847 times.This indicates that the TiO2 coated W18O49 nanorod material has greatly improved the photoelectric performance of the device and has good potential of application in the field of photoelectric detection. |
PDF Full Text Request