Noble Metal Chalcogenides By Thermal Deposition And Their Photoelectric Application

Photoelectric devices are an indispensable part of the semiconductor industry,which are widely used in national defense and civil fields,such as optoelectronic detection,optical communication,near infrared imaging,semiconductor laser and clean energy.Two-dimensional transition metal sulfides(such as Mo S₂,WS₂)are one of the important cornerstones of high-performance optoelectronics,which have amazing electronic and optoelectronic properties,such as adjustable band gaps,perfect surface structure,excellent mechanical flexibility and excellent carrier mobility.At the same time,noble metal chalcogenide compounds（such as palladium diselenide,platinum sulfide,etc）are new members of the two-dimensional material family,with unique and rich physical and chemical properties,in which palladium diselenide has an adjustable band gaps and high air stability.its device performance is better than that of other transition metal chalcogenide compounds.Platinum sulfide is a new type of non-layered transition metal chalcogenide compounds with ultra-thin geometry and ultra-fast saturable absorption.Platinum sulfide also has great application potential in the fields of electronics and sensors.High quality chalcogenide compounds with good large area consistency can significantly improve the performance of electronic and photoelectric devices.At present,there are few detailed reports on the large area growth strategies of wafer size of precious metal chalcogenide compounds,and their synthesis is still challenging.In view of the above key problems,this paper aims to solve the problem of controllable preparation of precious metal chalcogenide compounds,and explores the large-scale preparation methods of palladium diselenide and platinum sulfide,the structure-activity relationship and performance improvement of electronic devices and photoelectric devices.The details are as follows:1.Preparation of wafer-grade palladium diselenide and photodetectors:（1）large size palladium diselenide was successfully prepared by direct selenization in a horizontal tube furnace by evaporating palladium diselenide thin films on the substrate.The effects of temperature,precursor thickness,gas and temperature flow rate in the tube furnace on palladium diselenide materials were investigated,and the growth temperature suitable for high-quality palladium diselenide was determined.（2）the electrical properties of palladium diselenide-based field effect transistors are studied,and the hole mobility of 176 cm² V^-1 s^-1 and the electron mobility of 247 cm² V^-1 s^-1are obtained.（3）the photodetector based on palladium diselenide is constructed,and the high responsivity and high detectivity are obtained,which are 1.15×10³ m A W^-1and 8.13×10¹⁰Jones,respectively.It provides high-quality materials for low-dimensional optoelectronic devices.2.Platinum sulfide and photodetectors were prepared by direct vulcanization:（1）the homogeneity of platinum sulfide materials was ensured by using fully covered thin film platinum metal as precursors,and the surface roughness of platinum sulfide was reduced by hydrogen sulfide atmosphere.The large-area preparation of platinum sulfide materials was realized.Scanning transmission electron microscopy was used to study its morphology,structure,and optical absorption.Through theoretical calculation,the competitive growth mechanism of platinum sulfide and platinum disulfide during vulcanization was studied,and the preferential growth temperature and sulfur partial pressure conditions of platinum sulfide were obtained.（2）the platinum sulfide photodetector is constructed and the thickness-performance relationship is studied.It is found that the thickness of the optimum platinum sulfide photodetector is 10nm,and its responsivity and detectivity are 201 m A W^-1 and 5.3×10⁹Jones,respectively.The high-performance optoelectronic device is realized,which is of great significance to the basic research and practical technology of two-dimensional precious metal chalcogenide compounds.Based on the preparation of frontier noble metal chalcogenide compounds,this thesis provides a general method for the preparation of layered and non-layered noble metal chalcogenide compounds with good quality.The novel two-dimensional materials stimulate a variety of applications of electronics and optoelectronics and promote the wide application of the next generation of nanoelectronics.