Preparation Of Low-dimensional SnS₂/Bi₂S₃/CdS And Their Application Research In Flexible Photodetector

photodetectors as one of the important optoelectronic devices,it can convert light signals into electrical signals,which have been applied to various aspects of life and have received much attention.With the continuous development of the economy,people's demand for wearable electronic devices that are portable,integrated,and healthy has been continuously increased,and the market demand for flexible devices continues to grow.The development trend of modern flexible photodetectors requires that the device can still be used normally when it is bent,folded,and curled,and it is expected that it can have excellent performance such as high sensitivity and high stability.However,the current flexible optical detectors with the above-described properties are still faced with difficult device fabrication,high production costs,unsatisfactory performance,and other practical difficulties,which greatly limit their practical application.Therefore,there is urgent need to design and prepare ideal low-cost photosensitive materials.Due to the quantum size effect of nanomaterials,it is comparative with corresponding bulk materials possible to exhibit superior physical,chemical,and electrical properties such as light,electron and heat,providing an opportunity for us to design portable flexible photodetectors.In this paper,a simple hydrothermal method was used to synthesize the materials of low dimensional nanomaterials,and a series of tests were carried out to characterize the samples.The sample is fabricated on a flexible substrate by a simple suspension method,and the photoelectric performance of the device is tested by an electrochemical workstation.The research work of this paper mainly includes the following three aspects:?1?Two-dimensional?2D?SnS₂ is a candidate material for modern electronics and optoelectronics.Due to its non-toxicity and other characteristics,it has attracted researchers'attention.In this chapter,hexagonal SnS₂ nanoplates were prepared by hydrothermal method.The structure,morphology and composition of the synthesized products were characterized by X ray diffraction,scanning electron microscopy,X ray photoelectron spectroscopy and UV-Vis spectroscopy.At the same time,the sample is deposited on a flexible ITO electrode by a suspension method of liquid phase self-assembly to prepare a flexible optical detector.The spectral response of homemade flexible photodetectors to different flexural times?0,30,60,90,120 times?and different bending degrees?0°-180°?was studied by using 388nm monochromatic laser as the light source.It is found that it has good stability and good reproducibility.In addition,the self-made photodetector also shows the characteristics of low-cost,friendly environment and good performance in the wavelength range of visible light.Based on the above results,this study provides a possibility for the manufacture of low cost,flexible photodetectors.?2?The Bi₂S₃ nanomaterials were synthesized using a simple hydrothermal method using L-cysteine?a common and inexpensive amino acid?as S source.It is noteworthy that no nauseous odor?hydrogen sulfide?has appeared in our experiments,which is unavoidable in the synthesis of many sulphides.The Zennium electrochemical workstation was used to test the photoelectric conversion properties of the samples.The test current-time?I-t?curve demonstrates the device's excellent reproducibility of switching,and the current-time?I-t?curves at different bends?0-180°?show good flexibility.In this work,the nanostructure of yttrium sulfide has been incorporated into the field of flexible photoelectric conversion,and the application of chalcogenide nanomaterials in the field of flexible photoelectric conversion has been enriched.?3?CdS has a very good application prospect in photoelectric conversion,photoluminescence,nonlinear optics,light absorption and so on.We use thiourea as the sulfur source and polyvinylpyrrolidone?PVP?as the surface active agent to synthesize CdS nanomaterials by hydrothermal method.The prepared CdS materials were characterized by X-ray diffraction,scanning electron microscopy,transmission electron microscopy and X-ray photoelectron spectroscopy.The test results of optical and electrical properties show that the device exhibits good flexibility and repeatability,which satisfies people's requirements for bendability of the device in practical applications to some extent.