Emission Properties Regulation Of CdTe QDs-2D TMDs Heterojunctions

Recently,two-dimensional materials and their photodetectors have attracted extensive attention from researchers,especially transition metal chiogenates(TMDs),which have strong photomaterial interaction band gap covering visible-near-infrared band and other unique properties.Representative TMDs include Mo S₂,Mo Se₂,WS₂,WSe₂,et al.,they show superior photoelectric performance and have potential applications in the field of next-generation photonics optoelectronic devices.However,Mo S₂and other TMDs only exhibit direct bandgap semiconductor characteristics in the monollayer limit.As monollayer TMDs,they inevitably have the shortcoming of weak light absorption.To solve the above problems,we combined zero-dimensional semiconductor quantum dots(QDs)with two-dimensional TMDs to construct a new mixed-dimensional heterojunction,which effectively enhanced the optical absorption rate.Meanwhile,CdTe quantum dots were used to flexibly control the exciton states of TMDs and achieve QDs-TMDs at different temperatures and excitation powers.The band structure renormalization of heterojunction,the controllable regulation of luminescence properties and high performance photodetectors,further promote the application process of photonics photoelectronic nano devices the main content of this paper and the research results are as follows:1.The monolayer WS₂and the 0D CdTe-2D WS₂hybrid dimensional van der Waals force heterojunction constructed after dropping quantum dots were prepared respectively,and the experimental results,such as Raman peak position frequency shift PL enhanced fluorescence lifetime shortened light response enhancement,confirmed that the quantum dots in the heterostructure effectively changed the band alignment of TMDs.2.The excitation power and temperatude-dependent luminescence spectra of CdTe QDs-2D WS₂hybrid dimensional heterojunction were studied in detail,and it was found that CdTe quantum dots produced unique exciton regulation,which was different from the excitation power and temperatude-induced regulation.The existence of CdTe quantum dots increased the binding energy of WS₂charged excitons.The probability of radiation recombination is reduced and the saturation power is increased,leading to higher room for photoluminescence intensity growth.3.Constructed based on the structure of CdTe-Mo S₂heterogeneous devices,and compared the Mo S₂,showed more photocurrent response rate,and light and the light response of the saturated power density in the narrow,confirmed the CdTe quantum dots can increase charged exciton binding energy,the escape of free charge less,can occupy state density is not enough,therefore the photocurrent harden ahead of time.