The Preparation And Photoelectric Properties Of Low-dimensional Nanomaterials

The surface effect,interface effect,small size effect and quantum effect of nano-materials have great potential in the physical and chemical fields such as electricity,mechanics,magnetism and optics.Especially in the field of photodetectors,one-dimensional(1D)and two-dimensional(2D)nanomaterials have shown excellent performance.Based on such research background,we are committed to the study on the preparation and photoelectric properties of 1D and 2D nanomaterials.Here we mainly studied the properties of the flexible photodetectors based on HfSe3 nanobelts,HfSe3 nanobelts/graphene,HfS3 nanobelts and HfS3 nanobelts/graphene,and the synthesis and characterization of borone by chemical method.The studies are as follows:1.The HfSe3 nanobelts have been synthesized by chemical vapor transfer method.The polypropylene film has been used as the photodetectors' flexible substrate.The HfSe3 nanobelts photodetector exhibits a wide response from visible to near-infrared,and shows a highest sensitivity under 405 nm wavelength.The response is 1.1 ×10-4 mA/W at 405 nm,and the quantum efficiency is about 3.32×10-5%.We mixed the HfSe3 nanobelts with graphene oxide and reduced graphene,respectively,and then assembled them into flexible photodetectors to study the photoelectric properties.Under the illumination light of 405 nm,the response of HfSe3/graphene oxide photodetector is about 4.3×10-3 mA/W;the quantum efficiency is 1.3×10-3%,and the response of HfSe3/reduced graphene photodetector is 0.5 mA/W,the quantum yield is 0.15%.By mixing with graphene,the flexible photodetectors of the composites show an enhancement of photoresponsivity.2.The HfS3 nanobelts have been synthesized by chemical vapor transfer method.The HfS3 nanobelts photodetector exhibits a wide response from visible to near-infrared,and shows a highest sensitivity under 405 nm wavelength.The response is 0.11 mA/W at 405 nm,and the quantum efficiency is about 3.43×10-2%.We mixed the HfS3 nanobelts with graphene oxide and reduced graphene respectively,and then assembled them into flexible photodetectors to study the photoelectric properties.Under the illumination light of 405 nm,the response of HfS3/graphene oxide photodetector is about 0.92 mA/W,and the quantum efficiency is 0.28%;the response of HfS3/reduced graphene photodetector is 0.55 mA/W,and the quantum yield is 0.17%.By mixing with graphene,the flexible photodetectors of the composites show an enhancement of photoresponsivity.3.The Borone of few layers has been obtained by the thermolysis of BBr3.The XPS spectrum shows that there is a small amount of boron oxide in the material,but for the most part it is still boron.By adjusting the time and reaction quantity,the boron thickness has been reduced from several tens to 1 nm,which is close to the thickness of a single boron atom.