High-performance Photodetectors Array Based On PtSe₂/pyramid-Si Heterojunction And Its Applications

A photodetector is an important optoelectronic device that can capture an optical signal and convert it into an electrical signal.It has been widely used in many military and national economic fields such as imaging,optical communication,environmental monitoring,night vision and security check.Group-10 transition metal dicacogenides（TMDs）have garnered externsive attention due to their appealing features including tunable bandgap,high charge carrier mobility and excellent air stability.As a novel group-10 TMD,two-dimensional（2D）PtSe₂ possesses unique optoelectrical characteristics,and is very promising for realizing broadband high-performance photodetection.However,the study of integrated devices towards multifunctional optoelectronic applications is still in its infancy.The preparation of detector arrays with high integration and high performance is the current research hotspot and frontier direction.This thesis presents the successful preparation of patterned 2D PtSe₂ films with high-qualtiy and the fabrication of PtSe₂/pyramid-Si heterojunction photodetectors array.The optoelectrical performance is studied and the related applications are explored.The detailed studies are as follows:The large area patterned growth of 2D PtSe₂ films has been successfully achieved by using traditional UV photolithography and electron beam evaporation technology combined with thermal-assisted selenization method.The PtSe₂/pyramid-Si heterojunction photodetectors array is constructed,and various performance parameters of the device are investigated.The factors affecting the performance of the device,such as light absorption capability and interface passivation,are studied and illustrated by theoretical calculation.In addition,the photodetectors array displays outstanding uniformity and reproducibility in performance.Therefore,it can reliably record an image produced by the NIR light and monitor a moving optical signal,showing the great potential for applications in NIR imaging sensing and light trajectory tracking.The main innovations of this thesis are:（1）The patterned growth of large area 2D PtSe₂ films has been realized.（2）Pyramid-Si microstructure and interface passivation technology are empolyed to improve the performance of photodetectors.（3）The preliminary integration of photodetectors is realized,showing great potential in the applications of NIR image sensing and optical trajectory tracking.It is expected that this work can promote the development of integrated optoelectronic devices based on 2D materials and expand their application scope.