Fabrication And Photoelectrical Properties Of High-performance Indium Selenide Optoelectronic Device

Entering the information age,communications using optoelectronics as a carrier play a pivotal role in various fields of the national economy,and optoelectronic devices are receiving more and more attention.In recent years,photodetectors based on new twodimensional semiconductor materials have been favored by researchers because of their small size,low energy consumption,and high performance.Two-dimensional semiconductor materials are considered to be the construction materials of nextgeneration optoelectronic information devices due to their unique mechanical properties and excellent electron transport properties.Among many two-dimensional materials,indium selenide?In₂Se₃ and InSe₃?with high absorption coefficients,excellent electronic modulation capabilities,and good stability is like a rising star.However,the research on In₂Se₃-based optoelectronic devices is rare.In view of this,this article conducts systematic research taking indium selenide as the research object,from the characterization of material preparation,device preparation process,comprehensive performance improvement,new material growth mechanism explanation and performance exploration.In this paper,the two-dimensional In₂Se₃ material was successfully synthesized by atmospheric pressure chemical vapor deposition,and the entire process from the micronlevel single crystal to the centimeter-level thin film was precisely controlled by parameter adjustment.After various characterizations,it was determined to be high-quality ?-In₂Se₃.Subsequently,a dry material transfer technology was developed to solve the problem of the easy introduction of organic reagents in traditional wet transfer to cause the single crystal material to be contaminated and reduce the performance;combined with the metal-semiconductor contact theory,we selected metal gold as our electrode material to effectively reduced the barrier height;the basic process of preparing flexible In₂Se₃ photodetectors is successfully explored using laser direct write lithography technology and metal coating processes.Although single ultra-high-performance indicators have been achieved based on two-dimensional?2D?semiconductors,the comprehensive performances of the photodetectors of them are not so desirable.The response speed and responsivity are two key figures of merit for photodetectors,while these two parameters are always mutually suppressive and can not be synchronously satisfied.To solve this problem,this study analyzed the causes and applied mechanical strain to induce the piezoresistive effect,thereby achieving the purpose of regulating the energy band structure and barrier height.This study shows that under the wavelength range of 200-1000 nm and strains of 0.65%,the response value in the tensile state increases by an average of 68.6%,and the response value in the compressed state decreases by an average of 57.3%.More importantly,the response speed of the In₂Se₃-based photodetector has been significantly improved under two different strain states.The response time in the unstrained state is 244 ?s,the response time in the stretched state is reduced to 214 ?s,and the response time in the compressed state is reduced to 180 ?s.The results of this study prove that the strain engineering successfully achieved the goal of simultaneously improving the responsiveness and response speed of the In₂Se₃ photodetector,and provided a new solution for the optimization of the comprehensive performance of the photodetector.In the process of synthesizing materials,we adopted a new CVD synthesis method of vapor deposition and then selenization,and accidentally discovered a new material.After systematic characterization,the molecular structure of the new material was shown to be InSe₃.Subsequently,the crystal growth principle was used to analyze its growth mechanism,and with the help of this mechanism,the causes of various morphologies of InSe₃ were successfully explained.Next,we constructed the new material into an optoelectronic device.The current magnitude of the material at a source-drain voltage of 1 V was measured to be nanoamperes,the responsivity was about 0.65 A/W,and the detectivity was close to 10¹³ Jones.