| With the continuous development of electronic information technology,people’s demand for electronic devices is getting higher and higher,especially for miniaturization and fast response speed.The advent of two-dimensional materials provides novel ideas for the manufacture of photoelectronics and nanodevices with atomic thickness.The traditional ideology of nanoscience and nanotechnology has undergone revolutionary changes,and the expansion of the two-dimensional material family and the exploration of special properties have become a research hotspot.Among them,PtSe2,as a member of a new two-dimensional transition metal chalcogenide(TMDs)family,has attracted wide attention from researchers once it was discovered.PtSe2 is a typical layered two-dimensional material with strong interlayer interaction,and its properties will undergo a unique evolution from semiconductor to semi-metal as the thickness of the material increases.It has been proven to have high carrier mobility and good air stability,and has extremely high application prospects in the preparation of highperformance hybrid electronic devices,photoelectric detectors,and gas sensors.(1)Using chemical vapor deposition(CVD),a continuous large-area PtSe2 film with a size of about 2 cm×2 cm and a controllable thickness was successfully prepared.Characterization techniques such as atomic force microscopy(AFM),X-ray photoelectron spectroscopy(XPS),and Raman spectroscopy(Raman)were used to characterize the prepared film,which proved the high quality of the prepared PtSe2 film.The important parameters in the growth process were explored in detail,and the growth mechanism of PtSe2 films was explained from the perspectives of chemical kinetics and thermodynamics.Nano-platinum will agglomerate platinum metal during the heating process,resulting in the formation of discontinuous particulate PtSe2.In order to prevent the agglomeration of nano-platinum,adjust the heating rate,make Se and Pt react during the slow heating process to form a Se-Pt-Se bond to prevent the agglomeration of platinum.It is found that the growth temperature is 650℃ and the heating rate is 4℃/min,the PtSe2 film prepared when the holding time is 60 min has better filmforming properties.(2)The construction process of PtSe2 thin-film optoelectronic devices is introduced.Through the measurement of the arrayed PtSe2 thin-film optoelectronic devices,the Ids-Vds characteristic relationship of the P-type semiconductor which is dependent on the gate voltage is found.With stable and repeatable infrared broad-spectrum detection(532 nm-2200 nm),the internal mechanism of the increase of photocurrent and the decrease of responsivity with the increase of optical power is analyzed in detail.The photoelectric properties of PtSe2 films under different preparation conditions were further explored.It is found that the photoelectric response i-t diagram of the PtSe2 film prepared at 400℃has the highest signal-to-noise ratio and the best response,and the maximum response is 179.7 mA/w under 1550 nm wavelength detection.The PtSe2-BP van der Waals heterojunction was fabricated by a simple spincoating method,which further improved the photodetection performance of PtSe2.(3)The specific process of the electrocatalytic performance test of the PtSe2 film prepared by the chemical vapor deposition CVD method is introduced.Through the AFM topography and Raman diagram of the sample before and after the nondestructive transfer,it is proved that the sample morphology before and after the nondestructive transfer is not obvious.The well-ordered PtSe2 nanowall films with growth temperature of 550℃ show the enhanced HER performance,which exposes more edge active sites at the nanowall structure.The highest HER performances are achieved with a η0 value of～61 mV and a Tafel slope of～52 mV·dec-1 by well-ordered PtSe2 nanowall films with the thickness of 5.1 nm.This work can encourage more works on fabricating 2D TMDs-based nanowall structure for enhanced HER performance. |
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